86 dB DR Cross-Coupled Time-Interleaved xx ADC for Audio Signal Band with 322 ΣA Current Consumption

An audio band sigma-delta ADC based on a new time-interleaved xx scheme isdescribed. The circuit achieves a very low power operation with the large dynamic range required for audio applications. This modified two channel time-interleaved scheme improves the power efficiency thanks to halved operating frequency in the paths, and a reduced number of levels in ADC and DAC. This sigma-delta modulator fabricated in a 0.18 μm CMOS process uses 1.8 V supply and ±0.5 V input range. Experimental results show that with a 35 dBFS input sine wave there are no tones above a 110 dB noise floor.