A 16b Oversampling CODEC With Filtering DSP

A precision low-power analog signal interface processor achieves 16b and 18b accuracy for A-to-D and D-to-A interfaces, respectively, at 25kHz signal bandwidth. The processor is realized by second-order noise-shaping A-to-D and D-to-A converters with an oversampling ratio of 256 and DSP optimized for filtering operations. The chip operates with single 5V power supply and consumes 200mW. Previously-reported devices realize only ADC or DAC, occupy large chip area, and consume high power.