Low-voltage double-sampled /spl Sigma//spl Delta/ converters

In theory, double-sampling in second-order /spl Sigma//spl Delta/ analog-to-digital converters (ADC) can enhance the signal-to-noise ratio (SNR) by 15 dB. In practice however, the SNR performance is usually severely degraded because of mismatches occurring in switched-capacitors (SC). This paper introduces a simple method to solve this problem. Regarding /spl Sigma//spl Delta/ digital-to-analog converters (DAC), in addition to double-sampling, the accompanying use of internal decimation helps to relax the bandwidth requirements of the opamps. Both circuitries are to be operational to supply voltages as low as 1.5 V by using clock bootstrapping. Chip implementation is in double-poly, 2-metal technology featuring 0.5 /spl mu/m minimum channel lengths.