Allegro MicroSystems, Inc. Decides Not to Proceed with Initial Public Offering

Worcester, MA ¨C August 11, 2008 ¡ª Allegro MicroSystems, Inc. announced today that due to current market conditions it has decided not to pursue its proposed initial public offering of common stock at this time and to withdraw its registration statement on Form S-1 filed with the Securities and Exchange Commission. The registration statement covers the offering of shares of common stock to be newly issued by Allegro as well as shares of common stock owned by Sanken Electric Co., Ltd., the sole stockholder of Allegro.

Commenting on the decision not to proceed with its proposed initial public offering, Dennis H. Fitzgerald, Allegro¡¯s President and Chief Executive Officer said, ¡°Since we filed our initial registration statement last August, the capital markets have experienced significant deterioration, leading us to conclude that this is not the best time to conduct our initial public offering. We will reexamine whether to proceed with our IPO when market conditions improve.¡±

Mark Feragne, Allegro¡¯s Chief Financial Officer added, ¡°We continue to experience growth in our business. While we would have raised capital from the sale of some of our shares in the IPO, we possess sufficient capital to internally fund our current business and to support our growth objectives for the foreseeable future.¡±

About Allegro

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, 2008, Sanken had net sales of approximately 184.3 billion Japanese yen (approximately US$1.8 billion) and net profits of 1.8 billion Japanese yen (approximately US$18.0 million).

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