Coherent switching power for an analog circuit tester

摘要

A circuit tester stimulates an analog circuit device under test (DUT) with a test signal and periodically digitizes a resulting DUT output signal to produce an output data sequence that may be analyzed to ascertain DUT operating characteristics. The tester is powered by a switching power supply that induces periodic noise spikes in the DUT output signal. To eliminate the influence of the noise spikes on test results, the period of the switching power supply noise is made coherent with the digitization period. The phase of digitization is then adjusted so that the tester avoids digitizing the noise spikes in the DUT output signal.