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Proc-Type: 2001,MIC-CLEAR
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 BjWwn7LGbuMIjJZcRUAtf6Zwm0LMJMmpaP6EsAMWkvF1j8Y3eeDdhBCMfv2HD94i
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<SEC-DOCUMENT>0001209191-09-027661.txt : 20090522
<SEC-HEADER>0001209191-09-027661.hdr.sgml : 20090522
<ACCEPTANCE-DATETIME>20090519202557
ACCESSION NUMBER:		0001209191-09-027661
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20090515
FILED AS OF DATE:		20090519
DATE AS OF CHANGE:		20090519

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Caulfield Thomas
		CENTRAL INDEX KEY:			0001342570

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-31311
		FILM NUMBER:		09840850

	MAIL ADDRESS:	
		STREET 1:		4000 NORTH FIRST STREET
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PDF SOLUTIONS INC
		CENTRAL INDEX KEY:			0001120914
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER PROGRAMMING SERVICES [7371]
		IRS NUMBER:				251701361
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		333 WEST SAN CARLOS STREET
		STREET 2:		SUITE 700
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110
		BUSINESS PHONE:		4082807900

	MAIL ADDRESS:	
		STREET 1:		333 WEST SAN JOSE STREET
		STREET 2:		SUITE 700
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-05-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001120914</issuerCik>
        <issuerName>PDF SOLUTIONS INC</issuerName>
        <issuerTradingSymbol>PDFS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001342570</rptOwnerCik>
            <rptOwnerName>Caulfield Thomas</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>333 WEST SAN CARLOS STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 700</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95110</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10715</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This amount includes 10,715 shares of restricted stock rights (&quot;RSRs&quot;) that were previously reported as derivative securities in Table II on the Form 4/A filed on August 26, 2008. Each RSR represents a bookkeeping entry equal in value to one (1) share of common stock of PDF Solutions, Inc. that will be automatically settled in shares upon vesting of the RSR. This Form 4 is being filed in connection with the partial vesting of the RSRs on May 15, 2009 and to move the RSRs from Table II to Table I.</footnote>
    </footnotes>

    <remarks>Exhibit List:

Exhibit 24 - Confirming Statement</remarks>

    <ownerSignature>
        <signatureName>/s/ KEITH A. JONES, Substitute Attorney-in-Fact for Thomas Caulfield</signatureName>
        <signatureDate>2009-05-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24.4_287476
<SEQUENCE>2
<FILENAME>poa.txt
<DESCRIPTION>POA DOCUMENT
<TEXT>
CONFIRMING STATEMENT

	I, John K. Kibarian, (the "Attorney-in-Fact"), by virtue of the authority and
the full power of substitution given to me by Thomas Caulfield  (the "Section 16
Reporting Person") in and by the Power of Attorney previously executed by the
Section 16 Reporting Person (the "Power of Attorney"), do hereby appoint Joy E.
Leo and Keith A. Jones, or either of them signing singly, as the
Attorney-in-Fact's substitute (each a "Substitute Attorney-in-Fact") to exercise
all of the Attorney-in-Fact's powers provided for in the Power of Attorney,
including full power and authority to do and perform each and every act
requisite, necessary or convenient to be done in connection with such powers, as
fully, to all intents and purposes, as the Attorney-in-Fact might or could do
thereby.

	This Confirming Statement shall remain in full force and effect until the
earlier of (i) the Section 16 Reporting Person is no longer required to file
Forms 4 and 5 with respect to holdings of and transactions in securities issued
by PDF Solutions, Inc. (the "Company") (unless the Power of Attorney executed by
the Section 16 Reporting Person is earlier revoked by them in a signed writing
delivered to the Attorney-in-Fact), (ii) the Attorney-in-Fact terminates the
appointment of the Substitute Attorney-in-Fact or (iii) the
Substitute Attorney-in-Fact ceases to be an employee of the Company.

	IN WITNESS WHEREOF, the undersigned has caused this Confirming Statement to be
executed as of this 15th day of May, 2009.

    /s/ John K. Kibarian
__________________________________
JOHN K. KIBARIAN, Attorney-in-Fact
for Thomas Caulfield

</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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