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

Worcester, MA, August 8, 2007 ¡ª 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 MicroSystems, Inc.

Allegro MicroSystems, Inc. designs, develops, manufactures and markets magnetic sensor ICs and application-specific analog power semiconductors for the automotive, computer and office automation, communications, consumer and industrial markets. We are a leading provider, in terms of total net sales, of integrated Hall-Effect sensor ICs with applications in each of these markets. Our broad product portfolio of application-specific analog power ICs, includes motor drivers and power interface drivers that are used in automotive electronic systems and computer and office automation products, such as printers and LED displays. Our 40 years of experience in the semiconductor industry serves as our foundation for designing and manufacturing magnetic sensor ICs and analog power ICs, and enables our current expansion into the growing field of power management ICs. We are headquartered in Worcester, MA with design and applications centers located in the Americas, Asia, and Europe.

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).