US Patent 11621717 Non-linear inter-ADC calibration by time equidistant triggering

A calibration circuit, including: a first analog-to-digital converter (ADC) configured to sample a nonlinear reference signal continuously at an equidistant sampling rate to generate a reference sampled signal; a trigger timer configured to generate trigger signals; a second ADC configured to sample a point of each of the nonlinear reference signal and repeated versions of the nonlinear reference signal in response to the respective trigger signals at equidistantly increasing delays, to generate a device-under-test (DUT) sampled voltage; and processing circuitry configured to estimate a differential nonlinearity (DNL) of the DUT sampled signal, estimate a DNL of the reference sampled signal, and compare the estimated DNL of the DUT sampled signal with the estimated DNL of the reference sampled signal, to generate a DNL performance indication signal of the second ADC.