Apparatus and method for auto-zeroing a sampled comparator

A comparator compares an input voltage and a reference voltage and generates an output based on the comparison. The comparator may receive the input voltage in a normal mode of operation. Voltage band circuitry provides first and second test voltages to the comparator. The test voltages define a band around the reference voltage. An integrator adjusts an offset correction signal provided to the comparator based on outputs of the comparator that are generated using the test voltages. The output of the comparator that is generated using the first test voltage could be generated during a first auto-zeroing cycle. The output of the comparator that is generated using the second test voltage could be generated during a second auto-zeroing cycle. This technique helps to maintain the offset of the comparator with the band around the reference voltage.