Simple weight-integrating A/D converters with high noise rejection

It is shown that the use of simple weight-integrating functions (stepwise or triangle) in integrating A/D converters ensures a high level of noise rejection (NMRR-up to 80 dB if the actual period of power line-related noise differs from its nominal value by less than ±1%). This result can be improved (with NMRR up to 90 dB and more) if the time of weight integration is synchronized with the actual or predicted noise period. Theoretical and experimental data are considered and discussed