Test Time Reduction for Nonlinearity Error Testing of Digital Potentiometer

Abstract

Nonlinearity test is composed of differential nonlinearity (DNL) and integral nonlinearity (INL). Nonlinearity error test for digital potentiometer can be very challenging, high resolution digital potentiometer requires larger sample size that will lead to longer test time and higher test cost. Thus, a test method for testing nonlinearity error of a digital potentiometer using automated test equipment (ATE) was developed to reduce the test time for the said parameters. A digital potentiometer of Analog Devices Inc, AD5144, was used on the evaluation. All measurements were within the datasheet specification, which shows that the measurements were accurate. With both DNL and INL measured accurately, a 7.476% test time reduction for nonlinearity error testing of digital potentiometer was achieved on the developed test method.