Patent ID: 7064693
Filing Date: 2006-06-20
Classification: H03F,H03M

Abstract:
1. A background-calibrated comparator, comprising: a random chopping comparator for comparing an input signal with a reference signal and outputting a digital signal that shows the comparison result; wherein the random chopping comparator is controlled by an external random sequence to randomly forward or reverse the polarity of the input offset voltage of the comparator without affecting the operation of the comparator; meanwhile, the input offset voltage of the random chopping comparator is adjusted by the external digital control signal; a calibration processor, whose input signal is the output signal of the random chopping comparator and the random sequence for controlling the polarity of the offset voltage; the output of the calibration processor is a digital control signal for adjusting the offset voltage of the random chopping comparator; the calibration processor operates with the comparator to dynamically calibrate the offset voltage of the comparator; and a random sequence generator, which generates a signal with possibility of forward or reverse to serve as a chopping signal of the random chopping comparator; the possibility of generating a forward or a reversed signal is random, and the probability of each is 50%.