A mixed decision

The US International Trade Commission has produced a mixed verdict in the patent infringement case between Cirrus Logic and UK-based Wolfson Microelectronics.

The US International Trade Commission (ITC) has produced a mixed verdict in the patent infringement case between Cirrus Logic and UK-based Wolfson Microelectronics.

First off, it found that three Wolfson audio digital-to-analogue converter products do infringe Cirrus’ US Patent No 6,011,501 (the ‘501 patent). In this case, the ITC has recommended a limited exclusion order against the products being imported into the US. The order is limited to ‘standalone’ products and does not extend to end-user products that incorporate the Wolfson devices.

Wolfson says, however, that the findings on the ‘501 patent will have no effect on its business. Two of the three affected products were made obsolete in early 2004 due to a lack of market demand. The third product was modified to remove the disputed feature.

The Commission also determined that Cirrus’ US Patent No 6,492, 928 (the ‘928 patent) is unenforceable because ‘highly material prior art’ was not disclosed to the US Patent and Trademark Office. Accordingly, there is no restriction on the sale of the products into the US.

‘The initial findings are an endorsement of Wolfson’s stance that the ‘928 patent is unenforceable. Since the Company no longer markets any products affected by the ‘501 patent allegations, the decision will have no effect on our business,’ said David Milne, CEO of Wolfson.

The initial determination of the ITC regarding the case is subject to review by the full Commission of the ITC which is expected to issue its final decision on 14 February 2005.