MANHASSET, N.Y. Wolfson Microelectronics plc has announced the U.S. International Trade Commission (ITC) has terminated an investigation regarding two patent infringement allegations made by Cirrus Logic Inc.
The ITC confirmed an initial determination made in November 2004 by an administrative law judge that Cirrus' US Patent No 6,492, 928 (the '928 patent) is unenforceable because the inventors intentionally withheld material from the U.S. Patent and Trademark Office. Consequently, there will be no restrictions on Wolfson (Edinburgh, U.K.) or its customers from the sale of the Wolfson products that were alleged to have infringed.
A limited exclusion order has been issued relating to Wolfson audio digital-to-analog converters that infringe Cirrus' U.S. Patent No 6,011,501 (the '501 patent), which are shipped directly into the U.S. The order does not extend to any third party product that incorporates any Wolfson product.
According to Wolfson, the limited exclusion order will have no effect on Wolfson's business as the company obsoleted two of the three affected products in early 2004 due to a lack of market demand. The company modified the third product to remove the disputed feature.