Austin, Texas-based Cirrus Logic Inc’s Crystal Semiconductor unit has filed suit against Analog Devices Inc alleging infringement on four delta-sigma technology patents in a broad range of digital-to-analogue and analogue-to-digital products, and unfair competition through the misrepresentation of products to customers: the suit also alleges that Analog is infringing on its mask work in the CS5501 analogue-to-digital converter chip.
