Efficient and accurate testing of analog-to-digital converters using oscillation-test method

TLDR

The test approach is applicable to all ADC types. The paper proposes a practical oscillation‑test strategy for ADCs. The method converts the ADC into an oscillator, uses its oscillation frequencies to monitor conversion rate, DNL, and INL at each quantization band edge, and eliminates the need for analog stimulus and precision signal generators. Simulations and practical implementation demonstrate that the oscillation‑test approach improves test accuracy and proves efficient for ADC testing.

Abstract

This paper describes a practical test approach for analog-to-digital converters (ADCs) based on the oscillation-test strategy. The oscillation-test is applied to convert the ADC under test to an oscillator. The oscillation frequencies are able to monitor the ADC conversion rate, differential nonlinearity (DNL) and integral nonlinearity (INL) at each quantization band edge (QBE). Using this method, no analog stimulus should be supplied and therefore the need for a costly precision signal generator is eliminated. Besides, as the oscillation frequency is evaluated using pure digital circuitry, test accuracy is increased. This test approach is not limited to a special kind of ADC. Simulations and practical implementation prove the efficiency of the proposed test approach for ADCs.