An ADC/DAC loopback testing methodology by DAC output offsetting and scaling

This paper presents a loopback methodology for static linearity testing of an ADC/DAC pair; the key idea is to raise the effective ADC and DAC resolution by scaling the DAC output. First, during ADC testing, we scale down the DAC output to achieve the needed test stimulus resolution and adjust the DAC output offset to cover the ADC full-scale range. Then, for DAC testing, we raise the effective ADC resolution by scaling up the DAC output. Both simulation and measurement results are presented to validate the proposed technique.