Self-Testing Second-Order Delta-Sigma Modulators Using Digital Stimulus

Single-bit second-order delta-sigma modulators are commonly used in high-resolution ADCs. Testing this type of modulator requires a high-resolution test stimulus, which is difficult to generate. This paper proposes a novel and robust technique to determine the performance of the modulator, which incorporates simple design-for-testability circuitry. This technique requires only digital stimulus to test the modulator. Hence, it is suitable as an analog signature analyzer used in Built-In Self-Test applications. Simulation results show that this technique is capable of accurately determining the performance of a second-order delta-sigma modulator ADC.