Eliminate External Sources To Measure DUT Noise

摘要

If a device's additive phase-noise contribution is known, engineers can more easily select individual components for their signal chain. They will feel confident that those devices-in aggregate-meet the phase-noise requirements for their complete system. In an application note titled, "The Residual Phase Noise Measurement," Analog Devices' David Brandon and John Cavey describe a technique to evaluate device-under-test (DUT) noise by removing external noise sources. A residual phase-noise setup is used to isolate and measure the additive phase-noise contribution of a device. Such a setup allows noise sources external to the DUT, such as power supplies or input clocks, to be canceled from the measurement.