Cirrus Logic sues Wolfson Microelectronics

US chip company Cirrus Logic has filed a patent infringement suit against UK-based Wolfson Microelectronics in the US District Court for the Southern District of California.

Cirrus Logic has filed a patent infringement suit against UK-based Wolfson Microelectronics in the US District Court for the Southern District of California.

The suit relates specifically to certain digital-to-analog converters designed by Wolfson. The complaint alleges that several Wolfson products that incorporate digital-to-analog converters infringe US Patent No. 6,492,928 and US Patent No. 6,011,501.

The former patent relates to power-up and power-down transient suppression that prevents annoying pops which accompany switching an audio system on and off. The latter refers to methods for processing data in a one-bit format.

The complaint seeks damages and requests a permanent injunction against Wolfson from making, using, offering to sell or selling in the US or importing into the US any infringing products.

‘Cirrus Logic has made substantial R&D investments to build a rich portfolio of intellectual property, and we will continue to solidify our competitive position through vigorous pursuit of companies we believe are infringing upon our patents,’ asserted David D. French, president and CEO.

Wolfson’s initial reaction was one of surprise. The company claimed that it had had no contact with Cirrus directly prior to learning of the suit.

After reviewing Cirrus’ allegations with its legal advisors, Wolfson then issued a statement saying that it believed the Cirrus claims had no merit and that it would be vigorously defending itself against Cirrus’ allegations.