Design of a Sigma-Delta A/D Converter for Battery Measurement Chip

In order to develop the accuracy of a battery measurement chip,based on BCD180 HLV compatible process,a Sigma-Delta A/D Converter for battery measurement chip was implemented.The modulator of the ADC adopted single loop three orders feedback structure and OSR of 256,the digital filter featured ripples within±0.001 dB in pass band and-100 dB attenuation in stop band.The ADC consumed a power of 4.67mW (0.935mA),and the layout area was 2.56mm×0.51 mm at 5Vsupply.It had an SNDR of 87 dB,an SFDR of 99.2dB and the accuracy 0.01% in 1kHz bandwidth.