A built-in self-test for ADC and DAC in a single-chip speech CODEC

Built-in self-test (BIST) has been applied to test an analog to digital converter (ADC) and a digital to analog converter (DAC) embedded in a DSP-core ASIC. The performance characteristics of the ADC and the DAC designed in according with the CCITT recommendations are measured using BIST. Three characteristics have been evaluated and the measured results have shown good agreement with measured results by conventional tests. In the BIST operation, the DSP-core generates input stimulus and analyzes output response. Therefore, test-time is reduced, analog or mixed-signal test equipment is not needed, and finally, test-cost is reduced compared with conventional test methods. This paper describes the BIST design and evaluational results