Allegro MicroSystems, Inc. Files Registration Statement for Initial Public Offering

Worcester, MA, August 8, 2007 — Allegro MicroSystems, Inc. announced today that it has filed a registration statement with the Securities and Exchange Commission for an initial public offering of its common stock. It is expected that a portion of the shares will be issued and sold by Allegro and a portion will be sold by its parent, Sanken Electric Co., Ltd.

The joint book-running managers of the offering will be Lehman Brothers Inc. and Daiwa Securities America Inc.

The offering will be made only by means of a prospectus. A written preliminary prospectus related to the offering may be obtained when available from the prospectus department of Lehman Brothers, c/o Broadridge Integrated Distribution Services, 1155 Long Island Avenue, Edgewood, NY 11717, email: qiana.smith@broadridge.com, Fax: 631-254-7140 or from Daiwa Securities America Inc., Financial Square, 32 Old Slip, New York, NY 10005-3538, Fax: 212-612-7120.

A registration statement relating to these securities has been filed with the Securities and Exchange Commission but has not yet become effective. These securities may not be sold nor may offers to buy be accepted prior to the time the registration statement becomes effective. This press release shall not constitute an offer to sell or a solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About Allegro

Allegro MicroSystems, Inc. is a leader in developing, manufacturing and marketing high-performance power and Hall-effect sensor integrated circuits. Allegro's innovative solutions serve high-growth applications within the automotive, communications, computer/office automation, consumer and industrial markets. Allegro is headquartered in Worcester, Massachusetts (USA) with design and applications centers located in North and South America, Asia, and Europe. Further information about Allegro can be found at www.allegromicro.com.

About Sanken Electric Co., Ltd.

Sanken Electric Co., Ltd., headquartered in Saitama-ken, Japan, is a diversified electronics manufacturer specializing in semiconductors, power modules and power supply equipment. Sanken’s semiconductor business segment includes power supply ICs, motor driver ICs, automotive ICs and discrete devices. For the year ended March 31, 2007, Sanken had net sales of approximately 203.8 billion Japanese yen (approximately US$1.7 billion) and net profits of 7.5 billion Japanese yen (approximately US$63.5 million).

Editorial Contact:
Stephanie Fennelly
Director - Marketing Communications
Tel: (508) 854-5363
sfennelly@allegromicro.com