The U.S. Department of Justice (DoJ) has asked Mitsubishi Electric\u2019s U.S. unit for information regarding sales of static RAM (SRAM) chips in the United States, the Japanese company said Monday.Mitsubishi Electric & Electronics U.S.A. received a subpoena from the DoJ, the company said without providing any further information.SRAM is typically used as a memory buffer in devices such as computers and hard-disk drives. It can retain data as long as power is supplied. That puts it between dynamic RAM (DRAM), which retains data with power but requires refreshing, and flash memory, which retains data even when power is not supplied.The company\u2019s SRAM business was spun off to Renesas Technology in 2003, and Mitsubishi currently holds a 45 percent stake in that company.The announcement comes less than a week after Cypress Semiconductor said it had been notified that the DoJ\u2019s antitrust division will be launching an investigation into the SRAM market. The DoJ is already probing price fixing in the DRAM market, and Mitsubishi Electric was contacted in May this year regarding that investigation, it said at the time.The DRAM investigation has uncovered evidence of price fixing by major chip makers bidding for business with big U.S. computer makers including Dell, Apple Computer, Hewlett-Packard and IBM. Several DRAM makers have been ordered to pay fines as high as US$300 million, and three Samsung executives agreed to serve prison time for the part they played in the price fixing.-Martyn Williams, IDG News Service (Tokyo Bureau)Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.