Background calibration of aperture center errors in analog to digital converters

摘要

A method of background calibration of aperture center errors in a data communication system is provided. In an implementation, in response to detection of a low sampler output (“0”) in between two high sampler outputs (“1”), the method includes: calculating a signal derivative of an ADC output signal at the time of the detected low output; and adjusting timing at a selected sampler based on the calculated signal derivative. In an example implementation, the method includes watching for bubbles in the thermometer code output, and estimating the first derivative of the signal at the time of the bubble, then estimating the sign of the errors. In an example implementation, the errors are used in a control loop to reduce the aperture center error.

主权项

1. A method of background calibration of aperture timing errors in a data communication system including an analog to digital converter (ADC) having a plurality of samplers, comprising:
in response to detection of a low sampler output (“0”) in between two high sampler outputs (“1”), the low and high sampler outputs being at the same sampler in the plurality of samplers: calculating a signal derivative of an ADC output signal at the time of the detected low output; and adjusting timing at a selected sampler based on the calculated signal derivative.