Patent ID: 8649419

Claim:
An apparatus comprising: a comparator having a control terminal, a first output terminal, and a second output terminal; and an offset compensator having: a measurement circuit that is coupled to a selection circuit; and a controller that is coupled to the control terminal of the comparator, the selection circuit, and the measurement circuit, wherein the controller controls the selection circuit such that the measurement circuit measures first and second propagation delays for signals on the first and second output terminals, and wherein, if there is a difference between the first and second propagation delays, the controller provides an adjustment to the comparator; wherein the measurement circuit further comprises a time-to-digital converter (TDC); wherein the selection circuit is coupled between the first and second output terminals of the comparator and the TDC; wherein the comparator further comprises a plurality of comparators that are each coupled to the selection circuit; wherein the selection circuit further comprises: a plurality of first stage multiplexers, wherein each first stage multiplexer is coupled to at least one of the comparators; and a second stage multiplexer that is coupled to each first stage multiplexer and to the TDC.