Design-for-test circuit for successive approximation analog-to-digital converters

摘要

The present invention provides a method (30) of testing analog-to-digital converters (ADCs) (12) that shortens the test time required to measure INL and DNL by advantageously converting the ADC (12) into a digital to analog converter (DAC) (10). The conversion from ADC to DAC is accomplished using a DfT test mode, which reconfigures the ADC into a DAC using a delta modulation circuit. Since DACs can be tested much more efficiently than ADCs, the ADC test time is substantially reduced by the invention.