<?xml version="1.0" encoding="US-ASCII"?>
<!-- RR Donnelley Xcelerate Taxonomy Schema, based on XBRL 2.1  http://www.rrdonnelley.com/ -->
<!-- Version: 6.21.0 -->
<!-- Round: 5 -->
<!-- Creation date: 2014-03-14T18:46:08Z -->
<!-- Copyright (c) 2005-2013 R.R. Donnelley &amp; Sons Company All Rights Reserved. -->
<schema xmlns="http://www.w3.org/2001/XMLSchema"
  xmlns:xbrli="http://www.xbrl.org/2003/instance"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  xmlns:us-gaap="http://fasb.org/us-gaap/2013-01-31"
  xmlns:us-types="http://fasb.org/us-types/2013-01-31"
  xmlns:vicr="http://vicorpower.com/20131231"
  xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric"
  xmlns:num="http://www.xbrl.org/dtr/type/numeric"
  xmlns:xbrldt="http://xbrl.org/2005/xbrldt"
  xmlns:country="http://xbrl.sec.gov/country/2013-01-31"
  xmlns:currency="http://xbrl.sec.gov/currency/2012-01-31"
  xmlns:dei="http://xbrl.sec.gov/dei/2013-01-31"
  xmlns:exch="http://xbrl.sec.gov/exch/2013-01-31"
  xmlns:invest="http://xbrl.sec.gov/invest/2013-01-31"
  xmlns:stpr="http://xbrl.sec.gov/stpr/2011-01-31"
  targetNamespace="http://vicorpower.com/20131231"
  elementFormDefault="qualified" attributeFormDefault="unqualified">
  <annotation>
    <appinfo>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DocumentandEntityInformation" id="DocumentandEntityInformation">
        <link:definition>101 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/StatementOfFinancialPositionClassified" id="Role_StatementOfFinancialPositionClassified">
        <link:definition>103 - Statement - Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/StatementOfFinancialPositionClassifiedParenthetical" id="Role_StatementOfFinancialPositionClassifiedParen">
        <link:definition>104 - Statement - Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/StatementOfIncome" id="Role_StatementOfIncome">
        <link:definition>105 - Statement - Consolidated Statements of Operations</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/StatementOfOtherComprehensiveIncome" id="Role_StatementOfOtherComprehensiveIncome">
        <link:definition>106 - Statement - Consolidated Statements of Comprehensive Income (Loss)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/StatementOfOtherComprehensiveIncomeParenthetical" id="Role_StatementOfOtherComprehensiveIncomeParen">
        <link:definition>107 - Statement - Consolidated Statements of Comprehensive Income (Loss) (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/StatementOfCashFlowsIndirect" id="Role_StatementOfCashFlowsIndirect">
        <link:definition>108 - Statement - Consolidated Statements of Cash Flows</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/StatementOfShareholdersEquityAndOtherComprehensiveIncome" id="Role_StatementOfShareholdersEquityAndOtherComprehensiveIncome">
        <link:definition>109 - Statement - Consolidated Statements of Equity</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsOrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" id="Role_NotesToFinancialStatementsOrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock">
        <link:definition>110 - Disclosure - Description of Business</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsSignificantAccountingPoliciesTextBlock" id="Role_NotesToFinancialStatementsSignificantAccountingPoliciesTextBlock">
        <link:definition>111 - Disclosure - Significant Accounting Policies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsDisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" id="Role_NotesToFinancialStatementsDisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock">
        <link:definition>112 - Disclosure - Stock-Based Compensation and Employee Benefit Plans</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock" id="Role_NotesToFinancialStatementsInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock">
        <link:definition>113 - Disclosure - Short-Term and Long-Term Investments</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsFairValueDisclosuresTextBlock" id="Role_NotesToFinancialStatementsFairValueDisclosuresTextBlock">
        <link:definition>114 - Disclosure - Fair Value Measurements</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsInventoryDisclosureTextBlock" id="Role_NotesToFinancialStatementsInventoryDisclosureTextBlock">
        <link:definition>115 - Disclosure - Inventories</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsPropertyPlantAndEquipmentDisclosureTextBlock" id="Role_NotesToFinancialStatementsPropertyPlantAndEquipmentDisclosureTextBlock">
        <link:definition>116 - Disclosure - Property, Plant and Equipment</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsOtherInvestmentsTextBlock" id="Role_NotesToFinancialStatementsOtherInvestmentsTextBlock">
        <link:definition>117 - Disclosure - Other Investments</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsGoodwillAndIntangibleAssetsDisclosureTextBlock" id="Role_NotesToFinancialStatementsGoodwillAndIntangibleAssetsDisclosureTextBlock">
        <link:definition>118 - Disclosure - Goodwill and Other Intangible Assets</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsRestructuringAndRelatedActivitiesDisclosureTextBlock" id="Role_NotesToFinancialStatementsRestructuringAndRelatedActivitiesDisclosureTextBlock">
        <link:definition>119 - Disclosure - Severance Charges</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsProductWarrantyDisclosureTextBlock" id="Role_NotesToFinancialStatementsProductWarrantyDisclosureTextBlock">
        <link:definition>120 - Disclosure - Product Warranties</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsStockholdersEquityNoteDisclosureTextBlock" id="Role_NotesToFinancialStatementsStockholdersEquityNoteDisclosureTextBlock">
        <link:definition>121 - Disclosure - Stockholders' Equity</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsOtherIncomeAndOtherExpenseDisclosureTextBlock" id="Role_NotesToFinancialStatementsOtherIncomeAndOtherExpenseDisclosureTextBlock">
        <link:definition>122 - Disclosure - Other Income, Net</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsIncomeTaxDisclosureTextBlock" id="Role_NotesToFinancialStatementsIncomeTaxDisclosureTextBlock">
        <link:definition>123 - Disclosure - Income Taxes</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsCommitmentsAndContingenciesDisclosureTextBlock" id="Role_NotesToFinancialStatementsCommitmentsAndContingenciesDisclosureTextBlock">
        <link:definition>124 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsSegmentReportingDisclosureTextBlock" id="Role_NotesToFinancialStatementsSegmentReportingDisclosureTextBlock">
        <link:definition>125 - Disclosure - Segment Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsQuarterlyFinancialInformationTextBlock" id="Role_NotesToFinancialStatementsQuarterlyFinancialInformationTextBlock">
        <link:definition>126 - Disclosure - Quarterly Results of Operations (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" id="Role_NotesToFinancialStatementsScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock">
        <link:definition>127 - Disclosure - Valuation and Qualifying Accounts</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsSignificantAccountingPoliciesTextBlockPolicies" id="Role_NotesToFinancialStatementsSignificantAccountingPoliciesTextBlockPolicies">
        <link:definition>128 - Disclosure - Significant Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsSignificantAccountingPoliciesTextBlockTables" id="Role_NotesToFinancialStatementsSignificantAccountingPoliciesTextBlockTables">
        <link:definition>129 - Disclosure - Significant Accounting Policies (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsDisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlockTables" id="Role_NotesToFinancialStatementsDisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlockTables">
        <link:definition>130 - Disclosure - Stock-Based Compensation and Employee Benefit Plans (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockTables">
        <link:definition>131 - Disclosure - Short-Term and Long-Term Investments (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsFairValueDisclosuresTextBlockTables" id="Role_NotesToFinancialStatementsFairValueDisclosuresTextBlockTables">
        <link:definition>132 - Disclosure - Fair Value Measurements (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsInventoryDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsInventoryDisclosureTextBlockTables">
        <link:definition>133 - Disclosure - Inventories (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsPropertyPlantAndEquipmentDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsPropertyPlantAndEquipmentDisclosureTextBlockTables">
        <link:definition>134 - Disclosure - Property, Plant and Equipment (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsGoodwillAndIntangibleAssetsDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsGoodwillAndIntangibleAssetsDisclosureTextBlockTables">
        <link:definition>135 - Disclosure - Goodwill and Other Intangible Assets (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsRestructuringAndRelatedActivitiesDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsRestructuringAndRelatedActivitiesDisclosureTextBlockTables">
        <link:definition>136 - Disclosure - Severance Charges (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsProductWarrantyDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsProductWarrantyDisclosureTextBlockTables">
        <link:definition>137 - Disclosure - Product Warranties (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsOtherIncomeAndOtherExpenseDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsOtherIncomeAndOtherExpenseDisclosureTextBlockTables">
        <link:definition>138 - Disclosure - Other Income, Net (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsIncomeTaxDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsIncomeTaxDisclosureTextBlockTables">
        <link:definition>139 - Disclosure - Income Taxes (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsCommitmentsAndContingenciesDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsCommitmentsAndContingenciesDisclosureTextBlockTables">
        <link:definition>140 - Disclosure - Commitments and Contingencies (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsSegmentReportingDisclosureTextBlockTables" id="Role_NotesToFinancialStatementsSegmentReportingDisclosureTextBlockTables">
        <link:definition>141 - Disclosure - Segment Information (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/NotesToFinancialStatementsQuarterlyFinancialInformationTextBlockTables" id="Role_NotesToFinancialStatementsQuarterlyFinancialInformationTextBlockTables">
        <link:definition>142 - Disclosure - Quarterly Results of Operations (Unaudited) (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureSignificantAccountingPoliciesAdditionalInformation" id="DisclosureSignificantAccountingPoliciesAdditionalInformation">
        <link:definition>143 - Disclosure - Significant Accounting Policies - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureSignificantAccountingPoliciesComputationOfBasicAndDilutedIncomeLossPerShare" id="DisclosureSignificantAccountingPoliciesComputationOfBasicAndDilutedIncomeLossPerShare">
        <link:definition>144 - Disclosure - Significant Accounting Policies - Computation of Basic and Diluted Income (Loss) Per Share (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureSignificantAccountingPoliciesComputationOfBasicAndDilutedIncomeLossPerShareParenthetical" id="DisclosureSignificantAccountingPoliciesComputationOfBasicAndDilutedIncomeLossPerShareParenthetical">
        <link:definition>145 - Disclosure - Significant Accounting Policies - Computation of Basic and Diluted Income (Loss) Per Share (Parenthetical) (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureStockBasedCompensationAndEmployeeBenefitPlansAdditionalInformation" id="DisclosureStockBasedCompensationAndEmployeeBenefitPlansAdditionalInformation">
        <link:definition>146 - Disclosure - Stock-Based Compensation and Employee Benefit Plans - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureStockBasedCompensationAndEmployeeBenefitPlansStockBasedCompensationExpense" id="DisclosureStockBasedCompensationAndEmployeeBenefitPlansStockBasedCompensationExpense">
        <link:definition>147 - Disclosure - Stock-Based Compensation and Employee Benefit Plans - Stock-Based Compensation Expense (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureStockBasedCompensationAndEmployeeBenefitPlansWeightedAverageAssumptionsForFairValueForStockOptions" id="DisclosureStockBasedCompensationAndEmployeeBenefitPlansWeightedAverageAssumptionsForFairValueForStockOptions">
        <link:definition>148 - Disclosure - Stock-Based Compensation and Employee Benefit Plans - Weighted-Average Assumptions for Fair Value for Stock Options (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureStockBasedCompensationAndEmployeeBenefitPlansSummaryOfTheActivityUnderTheVicorStockOptionPlans" id="DisclosureStockBasedCompensationAndEmployeeBenefitPlansSummaryOfTheActivityUnderTheVicorStockOptionPlans">
        <link:definition>149 - Disclosure - Stock-Based Compensation and Employee Benefit Plans - Summary of the Activity under the Vicor Stock Option Plans (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureStockBasedCompensationAndEmployeeBenefitPlansSummaryOfTheActivityUnderThePicorStockOptionPlans" id="DisclosureStockBasedCompensationAndEmployeeBenefitPlansSummaryOfTheActivityUnderThePicorStockOptionPlans">
        <link:definition>150 - Disclosure - Stock-Based Compensation and Employee Benefit Plans - Summary of the Activity under the Picor Stock Option Plans (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureStockBasedCompensationAndEmployeeBenefitPlansSummaryOfTheActivityUnderTheVIChipStockOptionPlans" id="DisclosureStockBasedCompensationAndEmployeeBenefitPlansSummaryOfTheActivityUnderTheVIChipStockOptionPlans">
        <link:definition>151 - Disclosure - Stock-Based Compensation and Employee Benefit Plans - Summary of the Activity under the VI Chip Stock Option Plans (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureStockBasedCompensationAndEmployeeBenefitPlansSummaryOfTheActivityUnderTheVIChipStockOptionPlansParenthetical" id="DisclosureStockBasedCompensationAndEmployeeBenefitPlansSummaryOfTheActivityUnderTheVIChipStockOptionPlansParenthetical">
        <link:definition>152 - Disclosure - Stock-Based Compensation and Employee Benefit Plans - Summary of the Activity under the VI Chip Stock Option Plans (Parenthetical) (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureShortTermAndLongTermInvestmentsAdditionalInformation" id="DisclosureShortTermAndLongTermInvestmentsAdditionalInformation">
        <link:definition>153 - Disclosure - Short-Term and Long-Term Investments - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureShortTermAndLongTermInvestmentsSummaryOfAvailableforSaleSecurities" id="DisclosureShortTermAndLongTermInvestmentsSummaryOfAvailableforSaleSecurities">
        <link:definition>154 - Disclosure - Short-Term and Long-Term Investments - Summary of Available-for-Sale Securities (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureShortTermAndLongTermInvestmentsAmortizedCostAndEstimatedFairValueOfAvailableforSaleSecurities" id="DisclosureShortTermAndLongTermInvestmentsAmortizedCostAndEstimatedFairValueOfAvailableforSaleSecurities">
        <link:definition>155 - Disclosure - Short-Term and Long-Term Investments - Amortized Cost and Estimated Fair Value of Available-for-Sale Securities (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureShortTermAndLongTermInvestmentsRollForwardOfCreditLossRecognizedInEarningsOnAvailableforSaleAuctionRateSecurities" id="DisclosureShortTermAndLongTermInvestmentsRollForwardOfCreditLossRecognizedInEarningsOnAvailableforSaleAuctionRateSecurities">
        <link:definition>156 - Disclosure - Short-Term and Long-Term Investments - Roll Forward of Credit Loss Recognized in Earnings on Available-for-Sale Auction Rate Securities (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureFairValueMeasurementsAssetsMeasuredAtFairValueOnRecurringBasis" id="DisclosureFairValueMeasurementsAssetsMeasuredAtFairValueOnRecurringBasis">
        <link:definition>157 - Disclosure - Fair Value Measurements - Assets Measured at Fair Value on Recurring Basis (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformation" id="DisclosureFairValueMeasurementsAdditionalInformation">
        <link:definition>158 - Disclosure - Fair Value Measurements - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureFairValueMeasurementsQuantitativeInformationAboutLevel3FairValueMeasurements" id="DisclosureFairValueMeasurementsQuantitativeInformationAboutLevel3FairValueMeasurements">
        <link:definition>159 - Disclosure - Fair Value Measurements - Quantitative Information about Level 3 Fair Value Measurements (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureFairValueMeasurementsChangeInEstimatedFairValuesForAssetsValuedOnRecurringBasisUtilizingLevel3Inputs" id="DisclosureFairValueMeasurementsChangeInEstimatedFairValuesForAssetsValuedOnRecurringBasisUtilizingLevel3Inputs">
        <link:definition>160 - Disclosure - Fair Value Measurements - Change in Estimated Fair Values for Assets Valued on Recurring Basis Utilizing Level 3 Inputs (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureInventoriesSummaryOfInventories" id="DisclosureInventoriesSummaryOfInventories">
        <link:definition>161 - Disclosure - Inventories - Summary of Inventories (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosurePropertyPlantAndEquipmentAdditionalInformation" id="DisclosurePropertyPlantAndEquipmentAdditionalInformation">
        <link:definition>162 - Disclosure - Property, Plant and Equipment - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipment" id="DisclosurePropertyPlantAndEquipmentPropertyPlantAndEquipment">
        <link:definition>163 - Disclosure - Property, Plant and Equipment - Property, Plant and Equipment (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureOtherInvestmentsAdditionalInformation" id="DisclosureOtherInvestmentsAdditionalInformation">
        <link:definition>164 - Disclosure - Other Investments - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureGoodwillAndOtherIntangibleAssetsAdditionalInformation" id="DisclosureGoodwillAndOtherIntangibleAssetsAdditionalInformation">
        <link:definition>165 - Disclosure - Goodwill and Other Intangible Assets - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureGoodwillAndOtherIntangibleAssetsScheduleOfPatentCostAndOtherAsset" id="DisclosureGoodwillAndOtherIntangibleAssetsScheduleOfPatentCostAndOtherAsset">
        <link:definition>166 - Disclosure - Goodwill and Other Intangible Assets - Schedule of Patent Cost and Other Asset (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureSeveranceChargesAdditionalInformation" id="DisclosureSeveranceChargesAdditionalInformation">
        <link:definition>167 - Disclosure - Severance Charges - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureSeveranceChargesASummaryOfActivityRelatedToSeveranceCharges" id="DisclosureSeveranceChargesASummaryOfActivityRelatedToSeveranceCharges">
        <link:definition>168 - Disclosure - Severance Charges - A Summary of Activity Related to Severance Charges (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureProductWarrantiesProductWarrantyActivity" id="DisclosureProductWarrantiesProductWarrantyActivity">
        <link:definition>169 - Disclosure - Product Warranties - Product Warranty Activity (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureStockholdersEquityAdditionalInformation" id="DisclosureStockholdersEquityAdditionalInformation">
        <link:definition>170 - Disclosure - Stockholders' Equity - Additional information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureOtherIncomeNetComponentsOfOtherIncome" id="DisclosureOtherIncomeNetComponentsOfOtherIncome">
        <link:definition>171 - Disclosure - Other Income, Net - Components of Other Income (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureIncomeTaxesScheduleOfReconciliationOfFederalStatutoryRateToEffectiveIncomeTaxRate" id="DisclosureIncomeTaxesScheduleOfReconciliationOfFederalStatutoryRateToEffectiveIncomeTaxRate">
        <link:definition>172 - Disclosure - Income Taxes - Schedule of Reconciliation of Federal Statutory Rate to Effective Income Tax Rate (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureIncomeTaxesAdditionalInformation" id="DisclosureIncomeTaxesAdditionalInformation">
        <link:definition>173 - Disclosure - Income Taxes - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureIncomeTaxesScheduleOfDomesticAndForeignComponentsOfIncomeLossBeforeIncomeTaxes" id="DisclosureIncomeTaxesScheduleOfDomesticAndForeignComponentsOfIncomeLossBeforeIncomeTaxes">
        <link:definition>174 - Disclosure - Income Taxes - Schedule of Domestic and Foreign Components of Income (Loss) Before Income Taxes (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureIncomeTaxesScheduleOfComponentsOfProvisionBenefitForIncomeTaxes" id="DisclosureIncomeTaxesScheduleOfComponentsOfProvisionBenefitForIncomeTaxes">
        <link:definition>175 - Disclosure - Income Taxes - Schedule of Components of Provision (Benefit) for Income Taxes (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureIncomeTaxesScheduleOfSignificantComponentsOfDeferredTaxAssetsAndLiabilities" id="DisclosureIncomeTaxesScheduleOfSignificantComponentsOfDeferredTaxAssetsAndLiabilities">
        <link:definition>176 - Disclosure - Income Taxes - Schedule of Significant Components of Deferred Tax Assets and Liabilities (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureIncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefits" id="DisclosureIncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefits">
        <link:definition>177 - Disclosure - Income Taxes - Schedule of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureCommitmentsAndContingenciesSummaryOfFutureMinimumRentalCommitmentsUnderNonCancelableOperatingLeases" id="DisclosureCommitmentsAndContingenciesSummaryOfFutureMinimumRentalCommitmentsUnderNonCancelableOperatingLeases">
        <link:definition>178 - Disclosure - Commitments and Contingencies - Summary of Future Minimum Rental Commitments under Non-Cancelable Operating Leases (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformation" id="DisclosureCommitmentsAndContingenciesAdditionalInformation">
        <link:definition>179 - Disclosure - Commitments and Contingencies - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureSegmentInformationAdditionalInformation" id="DisclosureSegmentInformationAdditionalInformation">
        <link:definition>180 - Disclosure - Segment Information - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureSegmentInformationSignificantSegmentFinancialData" id="DisclosureSegmentInformationSignificantSegmentFinancialData">
        <link:definition>181 - Disclosure - Segment Information - Significant Segment Financial Data (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureQuarterlyResultsOfOperationsUnauditedSummaryOfUnauditedQuarterlyFinancialData" id="DisclosureQuarterlyResultsOfOperationsUnauditedSummaryOfUnauditedQuarterlyFinancialData">
        <link:definition>182 - Disclosure - Quarterly Results of Operations (Unaudited) - Summary of Unaudited Quarterly Financial Data (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureQuarterlyResultsOfOperationsUnauditedAdditionalInformation" id="DisclosureQuarterlyResultsOfOperationsUnauditedAdditionalInformation">
        <link:definition>183 - Disclosure - Quarterly Results of Operations (Unaudited) - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://vicorpower.com/taxonomy/role/DisclosureScheduleIIValuationAndQualifyingAccounts" id="DisclosureScheduleIIValuationAndQualifyingAccounts">
        <link:definition>184 - Disclosure - Schedule II - Valuation and Qualifying Accounts (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:type="simple" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:href="vicr-20131231_cal.xml" xlink:title="Calculation Links, all"/>
      <link:linkbaseRef xlink:type="simple" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:href="vicr-20131231_def.xml" xlink:title="Definition Links, all"/>
      <link:linkbaseRef xlink:type="simple" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:href="vicr-20131231_lab.xml" xlink:title="Label Links, all"/>
      <link:linkbaseRef xlink:type="simple" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:href="vicr-20131231_pre.xml" xlink:title="Presentation Links, all"/>
    </appinfo>
  </annotation>
  <import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd"/>
  <import namespace="http://fasb.org/us-types/2013-01-31" schemaLocation="http://xbrl.fasb.org/us-gaap/2013/elts/us-types-2013-01-31.xsd"/>
  <import namespace="http://www.xbrl.org/dtr/type/numeric" schemaLocation="http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd"/>
  <import namespace="http://www.xbrl.org/dtr/type/non-numeric" schemaLocation="http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd"/>
  <import namespace="http://fasb.org/us-gaap/2013-01-31" schemaLocation="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd"/>
  <import namespace="http://xbrl.sec.gov/country/2013-01-31" schemaLocation="http://xbrl.sec.gov/country/2013/country-2013-01-31.xsd"/>
  <import namespace="http://xbrl.sec.gov/currency/2012-01-31" schemaLocation="http://xbrl.sec.gov/currency/2012/currency-2012-01-31.xsd"/>
  <import namespace="http://xbrl.sec.gov/dei/2013-01-31" schemaLocation="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd"/>
  <import namespace="http://xbrl.sec.gov/exch/2013-01-31" schemaLocation="http://xbrl.sec.gov/exch/2013/exch-2013-01-31.xsd"/>
  <import namespace="http://xbrl.sec.gov/invest/2013-01-31" schemaLocation="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd"/>
  <import namespace="http://xbrl.sec.gov/stpr/2011-01-31" schemaLocation="http://xbrl.sec.gov/stpr/2011/stpr-2011-01-31.xsd"/>
  <element name="AgeOfEmployeesOrDirectors" id="vicr_AgeOfEmployeesOrDirectors" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AggregateTemporaryImpairmentLoss" id="vicr_AggregateTemporaryImpairmentLoss" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AmortizedCostAndFairValueDebtSecuritiesAbstract" id="vicr_AmortizedCostAndFairValueDebtSecuritiesAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AmountOfPrejudgmentInterestPaid" id="vicr_AmountOfPrejudgmentInterestPaid" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AmountPaidForAffirmingAward" id="vicr_AmountPaidForAffirmingAward" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AuctionFailedSecuritiesUnrealizedLossPositionMinimumPeriod" id="vicr_AuctionFailedSecuritiesUnrealizedLossPositionMinimumPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AvailableForSaleSecuritiesDebtMaturitiesYearTenThroughTwentyAmortizedCostBasis" id="vicr_AvailableForSaleSecuritiesDebtMaturitiesYearTenThroughTwentyAmortizedCostBasis" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AvailableForSaleSecuritiesDebtMaturitiesYearTenThroughTwentyFairValue" id="vicr_AvailableForSaleSecuritiesDebtMaturitiesYearTenThroughTwentyFairValue" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AvailableForSaleSecuritiesDebtMaturitiesYearTwentyThroughFortyAmortizedCostBasis" id="vicr_AvailableForSaleSecuritiesDebtMaturitiesYearTwentyThroughFortyAmortizedCostBasis" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AvailableForSaleSecuritiesDebtMaturitiesYearTwentyThroughFortyFairValue" id="vicr_AvailableForSaleSecuritiesDebtMaturitiesYearTwentyThroughFortyFairValue" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AvailableForSaleSecuritiesDebtMaturitiesYearTwoThroughTenAmortizedCostBasis" id="vicr_AvailableForSaleSecuritiesDebtMaturitiesYearTwoThroughTenAmortizedCostBasis" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AvailableForSaleSecuritiesDebtMaturitiesYearTwoThroughTenFairValue" id="vicr_AvailableForSaleSecuritiesDebtMaturitiesYearTwoThroughTenFairValue" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AvailableForSaleSecuritiesGrossUnrealizedGainsAccumulatedInInvestments" id="vicr_AvailableForSaleSecuritiesGrossUnrealizedGainsAccumulatedInInvestments" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AvailableForSaleSecuritiesGrossUnrealizedLossAccumulatedInInvestments" id="vicr_AvailableForSaleSecuritiesGrossUnrealizedLossAccumulatedInInvestments" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="BbuMember" id="vicr_BbuMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="BrokeredCertificatesOfDepositMember" id="vicr_BrokeredCertificatesOfDepositMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CapitalExpenditureCommitments" id="vicr_CapitalExpenditureCommitments" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CashAndCashEquivalentsMaturityPeriods" id="vicr_CashAndCashEquivalentsMaturityPeriods" type="xbrli:stringItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ChipOptionsActuallyVest" id="vicr_ChipOptionsActuallyVest" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ChipOptionsActuallyVestForfeiture" id="vicr_ChipOptionsActuallyVestForfeiture" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CommonStockVotesPerShare" id="vicr_CommonStockVotesPerShare" type="xbrli:decimalItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CumulativeProbabilityOfDefaultMember" id="vicr_CumulativeProbabilityOfDefaultMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CumulativeProbabilityOfEarningMaximumRateUntilMaturityMember" id="vicr_CumulativeProbabilityOfEarningMaximumRateUntilMaturityMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CumulativeProbabilityOfPrincipalReturnPriorToMaturityMember" id="vicr_CumulativeProbabilityOfPrincipalReturnPriorToMaturityMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CustomerOneMember" id="vicr_CustomerOneMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CustomerTwoMember" id="vicr_CustomerTwoMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DecreaseInFairValueOfFailedAuctionSecurities" id="vicr_DecreaseInFairValueOfFailedAuctionSecurities" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DeferredRevenueRecognitionPeriod" id="vicr_DeferredRevenueRecognitionPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DeferredTaxAssetsLiabilitiesLineItems" id="vicr_DeferredTaxAssetsLiabilitiesLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DeferredTaxAssetsLiabilitiesTable" id="vicr_DeferredTaxAssetsLiabilitiesTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="DeferredTaxAssetsTaxCreditCarryforwardsInvestments" id="vicr_DeferredTaxAssetsTaxCreditCarryforwardsInvestments" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DeferredTaxAssetsTaxVacationAccrual" id="vicr_DeferredTaxAssetsTaxVacationAccrual" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DeferredTaxAssetsUnrealizedLossOnInvestments" id="vicr_DeferredTaxAssetsUnrealizedLossOnInvestments" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DeferredTaxAssetsValuationAllowanceIncrease" id="vicr_DeferredTaxAssetsValuationAllowanceIncrease" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DeferredTaxLiabilitiesUnremittedCustomEarnings" id="vicr_DeferredTaxLiabilitiesUnremittedCustomEarnings" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DividendPaidToShareholder" id="vicr_DividendPaidToShareholder" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DocumentAndEntityInformationAbstract" id="vicr_DocumentAndEntityInformationAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EffectiveIncomeTaxRateReconciliationIncreaseDecreaseTaxReserves" id="vicr_EffectiveIncomeTaxRateReconciliationIncreaseDecreaseTaxReserves" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EffectiveIncomeTaxRateReconciliationPermanentItems" id="vicr_EffectiveIncomeTaxRateReconciliationPermanentItems" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EmployeesAndDirectorsMember" id="vicr_EmployeesAndDirectorsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EmployeeServiceShareBasedCompensationAwardsCompensationCostsSubjectToImmediateRecognitionDueToAgeOfRecipient" id="vicr_EmployeeServiceShareBasedCompensationAwardsCompensationCostsSubjectToImmediateRecognitionDueToAgeOfRecipient" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EmployeeServiceShareBasedCompensationNonvestedAwardsExpectedCompensationCostRecognizedStockOptionsYearFive" id="vicr_EmployeeServiceShareBasedCompensationNonvestedAwardsExpectedCompensationCostRecognizedStockOptionsYearFive" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EmployeeServiceShareBasedCompensationNonvestedAwardsExpectedCompensationCostRecognizedStockOptionsYearFour" id="vicr_EmployeeServiceShareBasedCompensationNonvestedAwardsExpectedCompensationCostRecognizedStockOptionsYearFour" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EmployeeServiceShareBasedCompensationNonvestedAwardsExpectedCompensationCostRecognizedStockOptionsYearOne" id="vicr_EmployeeServiceShareBasedCompensationNonvestedAwardsExpectedCompensationCostRecognizedStockOptionsYearOne" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EmployeeServiceShareBasedCompensationNonvestedAwardsExpectedCompensationCostRecognizedStockOptionsYearThree" id="vicr_EmployeeServiceShareBasedCompensationNonvestedAwardsExpectedCompensationCostRecognizedStockOptionsYearThree" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EmployeeServiceShareBasedCompensationNonVestedAwardsExpectedCompensationCostRecognizedStockOptionsYearTwo" id="vicr_EmployeeServiceShareBasedCompensationNonVestedAwardsExpectedCompensationCostRecognizedStockOptionsYearTwo" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EntityWideAccountReceivableMajorCustomerPercentage" id="vicr_EntityWideAccountReceivableMajorCustomerPercentage" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EquityImpactDueToRealizationOfDeferredTaxAssets" id="vicr_EquityImpactDueToRealizationOfDeferredTaxAssets" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EstimatedTimeframeForAuctionsOfSecuritiesMaximum" id="vicr_EstimatedTimeframeForAuctionsOfSecuritiesMaximum" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EstimatedTimeframeForAuctionsOfSecuritiesMinimum" id="vicr_EstimatedTimeframeForAuctionsOfSecuritiesMinimum" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ExcessTaxBenefitDeficiencyFromShareBasedCompensationFinancingActivities" id="vicr_ExcessTaxBenefitDeficiencyFromShareBasedCompensationFinancingActivities" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FairValueAssetsMeasuredOnRecurringBasisRedemptionsAtPar" id="vicr_FairValueAssetsMeasuredOnRecurringBasisRedemptionsAtPar" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FairValueAvailableForSaleOfSecuritiesRedemption" id="vicr_FairValueAvailableForSaleOfSecuritiesRedemption" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FairValueMeasurementUnobservableInput" id="vicr_FairValueMeasurementUnobservableInput" type="xbrli:stringItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FairValueOfAssetsAndLiabilitiesMeasuredOnNonRecurringBasisLineItems" id="vicr_FairValueOfAssetsAndLiabilitiesMeasuredOnNonRecurringBasisLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FederalNetOperatingLossCarryforwardsExpirationYear" id="vicr_FederalNetOperatingLossCarryforwardsExpirationYear" type="xbrli:gYearItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FiscalYearAxis" id="vicr_FiscalYearAxis" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:dimensionItem"/>
  <element name="FiscalYearDomain" id="vicr_FiscalYearDomain" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="GrossAmountPaidByInsuranceCarriers" id="vicr_GrossAmountPaidByInsuranceCarriers" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="GrossDeferredCostOfRevenue" id="vicr_GrossDeferredCostOfRevenue" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncomeTaxExaminationPeriod1" id="vicr_IncomeTaxExaminationPeriod1" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncreaseDecreaseInAccruedSeveranceLiabilities" id="vicr_IncreaseDecreaseInAccruedSeveranceLiabilities" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncreaseDecreaseInLongTermIncomeTaxesPayable" id="vicr_IncreaseDecreaseInLongTermIncomeTaxesPayable" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncreaseDecreaseInOperatingDeferredRevenue" id="vicr_IncreaseDecreaseInOperatingDeferredRevenue" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncreaseInInventoryValuationReserves" id="vicr_IncreaseInInventoryValuationReserves" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncreaseOrDecreaseFairValueOfFailedAuctionSecurities" id="vicr_IncreaseOrDecreaseFairValueOfFailedAuctionSecurities" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncreaseOrDecreaseInLiquidityRiskPremium" id="vicr_IncreaseOrDecreaseInLiquidityRiskPremium" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="InterestRatesAuctionPeriod" id="vicr_InterestRatesAuctionPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LiabilityStockOptionAwardsReclassifiedToEquity" id="vicr_LiabilityStockOptionAwardsReclassifiedToEquity" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LikelihoodPercentageOfTaxBenefitUponSettlement" id="vicr_LikelihoodPercentageOfTaxBenefitUponSettlement" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LiquidityRiskPremiumMember" id="vicr_LiquidityRiskPremiumMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LossContingencyReductionInDamagesAwardedValue" id="vicr_LossContingencyReductionInDamagesAwardedValue" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="MaturityPeriodOfTreasuryBond" id="vicr_MaturityPeriodOfTreasuryBond" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NonPerformanceBasedStockOptionMember" id="vicr_NonPerformanceBasedStockOptionMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfCustomers" id="vicr_NumberOfCustomers" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfCustomersAccountedForTradeAccountReceivable" id="vicr_NumberOfCustomersAccountedForTradeAccountReceivable" type="xbrli:integerItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfDistributors" id="vicr_NumberOfDistributors" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfEligibleParticipantsAcceptedOptionExchangeOffer" id="vicr_NumberOfEligibleParticipantsAcceptedOptionExchangeOffer" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfEntitiesComprisingOperatingSegment" id="vicr_NumberOfEntitiesComprisingOperatingSegment" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfSharesExchangedUnderShareExchangeAgreement" id="vicr_NumberOfSharesExchangedUnderShareExchangeAgreement" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfSharesExchangedUnderShareExchangeAgreementPercentage" id="vicr_NumberOfSharesExchangedUnderShareExchangeAgreementPercentage" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OtherInvestmentPolicyTextBlock" id="vicr_OtherInvestmentPolicyTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OtherInvestmentsTextBlock" id="vicr_OtherInvestmentsTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PatentRenewalFees" id="vicr_PatentRenewalFees" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PercentageOfCreditLoss" id="vicr_PercentageOfCreditLoss" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PercentageOfLiquidityRiskPremium" id="vicr_PercentageOfLiquidityRiskPremium" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PerformanceBasedOptionsMember" id="vicr_PerformanceBasedOptionsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PeriodForWhichFailedAuctionSecuritiesBeenInUnrealizedLossPosition" id="vicr_PeriodForWhichFailedAuctionSecuritiesBeenInUnrealizedLossPosition" type="xbrli:stringItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PicorMember" id="vicr_PicorMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PicorOptionsActuallyVest" id="vicr_PicorOptionsActuallyVest" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PicorOptionsActuallyVestForfeiture" id="vicr_PicorOptionsActuallyVestForfeiture" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PicorPlanMember" id="vicr_PicorPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PicorStockOptionsMember" id="vicr_PicorStockOptionsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ProductWarrantyPeriods" id="vicr_ProductWarrantyPeriods" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PropertyPlantAndEquipmentUsefulLifeAndValuesAbstract" id="vicr_PropertyPlantAndEquipmentUsefulLifeAndValuesAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RateOfReturnRequired" id="vicr_RateOfReturnRequired" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RecoveryRateInDefaultMember" id="vicr_RecoveryRateInDefaultMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RegulatoryAssetsAbstract" id="vicr_RegulatoryAssetsAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ReimbursementOfLossFromInsurance" id="vicr_ReimbursementOfLossFromInsurance" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ResearchTaxCreditCarryforwardExtensionPeriod" id="vicr_ResearchTaxCreditCarryforwardExtensionPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RevenueRecognitionAsPercentageOfNetRevenue" id="vicr_RevenueRecognitionAsPercentageOfNetRevenue" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RevisionsOfEstimatedObligations" id="vicr_RevisionsOfEstimatedObligations" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfRestructuringReserveBySegmentTableTextBlock" id="vicr_ScheduleOfRestructuringReserveBySegmentTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SeveranceAndOtherChargesLineItems" id="vicr_SeveranceAndOtherChargesLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPercentage" id="vicr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPercentage" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardForfeitureRate" id="vicr_ShareBasedCompensationArrangementByShareBasedPaymentAwardForfeitureRate" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisePrice" id="vicr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisePrice" type="num:perShareItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePrice" id="vicr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePrice" type="num:perShareItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardTermOfAward" id="vicr_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermOfAward" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationExpenseForNonPerformanceBasedStockOptionsRecognitionPeriod" id="vicr_ShareBasedCompensationExpenseForNonPerformanceBasedStockOptionsRecognitionPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShortTermBrokeredCertificatesOfDepositMember" id="vicr_ShortTermBrokeredCertificatesOfDepositMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="StockBonusPlanMember" id="vicr_StockBonusPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="StockRepurchaseProgramReductionInAuthorizedRepurchaseAmount" id="vicr_StockRepurchaseProgramReductionInAuthorizedRepurchaseAmount" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SubsequentLossRecovery" id="vicr_SubsequentLossRecovery" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TenderOfferExpirationDate" id="vicr_TenderOfferExpirationDate" type="xbrli:dateItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TimeBasedOptionMember" id="vicr_TimeBasedOptionMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TrancheFiveMember" id="vicr_TrancheFiveMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TrancheFourMember" id="vicr_TrancheFourMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TranchesOneMember" id="vicr_TranchesOneMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TranchesThreeMember" id="vicr_TranchesThreeMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TranchesTwoMember" id="vicr_TranchesTwoMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandElevenMember" id="vicr_TwoThousandElevenMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandOnePicorPlanMember" id="vicr_TwoThousandOnePicorPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandPlanMember" id="vicr_TwoThousandPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandSevenViChipPlanMember" id="vicr_TwoThousandSevenViChipPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandTwelveMember" id="vicr_TwoThousandTwelveMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UnrealizedLossesOnShortTermAndLongTermInvestmentsLineItems" id="vicr_UnrealizedLossesOnShortTermAndLongTermInvestmentsLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UnrealizedLossesOnShortTermAndLongTermInvestmentsTable" id="vicr_UnrealizedLossesOnShortTermAndLongTermInvestmentsTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="ViChipMember" id="vicr_ViChipMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ViChipPlanMember" id="vicr_ViChipPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ViChipPlanOptionsMember" id="vicr_ViChipPlanOptionsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ViChipStockOptionsMember" id="vicr_ViChipStockOptionsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="VicorMember" id="vicr_VicorMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="VicorNineteenNinetyEightPlanMember" id="vicr_VicorNineteenNinetyEightPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="VicorOptionsActuallyVest" id="vicr_VicorOptionsActuallyVest" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="VicorPlanMember" id="vicr_VicorPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="VicorStockOptionsMember" id="vicr_VicorStockOptionsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="VicorTwoThousandPlanMember" id="vicr_VicorTwoThousandPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="WeightedAverageRateUseToMeasureFairValue" id="vicr_WeightedAverageRateUseToMeasureFairValue" type="num:percentItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
</schema>
