Systems and Methods of Low Offset Switched Capacitor Comparators

摘要

The disclosed systems and methods of low offset switched capacitor comparator reduce settling errors. The system operates in two major phases. During a first phase, the input voltage is sampled on the input capacitors and a differential amplifier is configured in a unity gain configuration to sample the amplifier offset. During the second phase, the input voltage difference is amplified at the output of the comparator. The amplifier transient sampling error is reduced by shorting the outputs of the differential amplifier for a shorting period at the start of the second phase. A clocked comparator at the output of the differential amplifier provides a fast comparison using internal positive feedback. The differential amplifier should have developed sufficient differential output voltage to overcome the offset of the clocked comparator.