Patent ID: 8928334
Filing Date: 2015-01-06
Classification: G01R

Abstract:
1. An apparatus, comprising: an asynchronous comparator coupled to receive a first input signal and a second input signal to provide a first digital output signal; wherein the first digital output signal includes frequency information for noise on the first input signal; a threshold voltage generator coupled to receive a first periodic signal and a second periodic signal; wherein the threshold voltage generator is configured to provide the second input signal as an analog voltage responsive to the first periodic signal; a sampling circuit coupled to receive the first digital output signal, a third periodic signal, and a fourth periodic signal; wherein the fourth periodic signal is related to the third periodic signal; wherein the sampling circuit is configured to sample the first digital output signal using the third periodic signal to provide a first sampling of the first digital output signal and configured to sample the first digital output signal using the fourth periodic signal to provide a second sampling of the first digital output signal; and a processor coupled to receive a delay signal, the first sampling, and the second sampling to determine a noise measurement signal for the first input signal.