Patent ID: 10009034

Abstract:
Methods and systems for an analog-to-digital converter with near-constant common mode voltage may comprise, in an analog-to-digital converter (ADC) having sampling switches on each of two input lines to the ADC, N double-sided and M single-sided switched capacitors on each input line: sampling an input voltage by closing the sampling switches, opening the sampling switches and comparing voltage levels between the input lines, iteratively switching the double-sided switched capacitors between a reference voltage (Vref) and ground, and iteratively switching the single-sided switched capacitors between ground and voltages that may equal Vref/2x where x ranges from 0 to m−1 and m is a number of single-sided switched capacitors per input line. A common mode offset of the ADC may be less than VADC_fs/128+VADC_fs/256+VADC_fs/512+VADC_fs/1024 when m equals 4 and where VADC_fs is the full-scale voltage of the ADC.