Investigation of Static Analog-to-Digital Converter Nonlinearity Measurement Using Histogram and Servo-Loop Method

Analog-to-Digital Converter (ADC) linearity tests are commonly expressed in terms of Integral Non-Linearity (INL) and Differential Non-Linearity (DNL). The two main techniques used for determining these metrics are histogram-based and servo-loop-based linearity tests. In this paper, we investigate the closed loop servo-loop method as an alternative to the open-loop histogram test method with a view towards adopting it for in-house ADC intellectual property characterization. The result shows the closed loop method is superior compared to open loop in terms of accuracy, at the cost of increased test time.