Monolithic Power Systems (MPS) (NASDAQ:MPWR), a fabless manufacturer of high-performance analog and mixed-signal semiconductors, has filed a patent infringement lawsuit with the U.S. District Court for the Central District of California against Chip Advanced Technology (CAT), a Taiwanese chipmaker.  MPS asserts that CAT has infringed an MPS patent that enables efficient low-voltage, low-current power conversions, such as DC-DC step-down converters. In the complaint, MPS seeks unspecified damages and a court-ordered injunction against future infringement by CAT.

Founded in November 2003, CAT specializes in analog IC of power management IC design and video interface/front-end solutions.  The company is headed by Hung-Chih Liu as president.  In July 2007, CAT joined with Faraday Technology in a design center collaboration.

MPS combines advanced process technology with its highly experienced analog designers to produce high-performance power management chips for DC-DC converters, LED drivers, Cold Cathode Fluorescent Lamp (CCFL) backlight controllers, Class D audio amplifiers, and Linear ICs. MPS products are used in computing and network communications products, LCD monitors and TVs, and a wide variety of consumer and portable electronics products. Founded in 1997, MPS is headquartered in San Jose, California with sales offices in Taiwan, China, Korea, Japan, and Europe, which operate under MPS International, Ltd.

MPS itself and its Taiwanese customer, ASUSTek Computer being sued by O2 Micro International (Nasdaq: OIIM).  MPS won the first round May 2007 when the court ruled the case was invalid. judgment also found that none of the accused MPS CCFL inverter controllers infringes O2 Micro's patent claims (U.S. patent number 6,396,722).  An appeal may be initiated by O2Micro.