EX-23.1 5 b65742axexv23w1.htm EX-23.1 CONSENT OF ERNST & YOUNG LLP

exv23w1

EXHIBIT 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the reference to our firm under the captions “Selected Consolidated Financial Data” and “Experts” and to the use of our report dated May 8, 2007, in Amendment No. 2 to the Registration Statement (Form S-1 No. 333-145254) and the related Prospectus of Allegro MicroSystems, Inc. dated January 29, 2007.

/s/ Ernst & Young LLP

Boston, Massachusetts
January 24, 2008