Patent ID: 8350737

Claim:
A method for dynamically calibrating a flash analog to digital converter, the analog to digital converter including a track and hold circuit and a plurality of comparators, comprising: converting an original digital reference signal to an analog reference signal oscillating between a first analog voltage and a second analog voltage at a calibration frequency; sampling the analog reference signal at the track and hold circuit; converting the sampled analog reference signal to a digitized reference signal by the plurality of analog comparators; converting the digitized reference signal to an under-sampled digitized reference signal, the under-sampled digitized signal being under-sampled at the calibration frequency divided by M, where M is a positive number; comparing the under-sampled digitized reference signal to the original digital reference signal; and adjusting a subsequent signal before it is received by the plurality of comparators based on the differences in the original digital reference signal and the under-sampled digitized reference signal.