Experimental verification of a correlation-based correction algorithm for multi-bit delta-sigma ADCs

A multi-chip system was built to provide experimental verification of a correlation-based digital algorithm, which acquires and corrects all element errors in the internal DAC of a multi-bit delta-sigma ADC. The proposed correction method does not rely on noise shaping, and hence it remains fully effective even for very low oversampling ratios (OSRs). Measured results obtained for OSR=4 confirmed that a 12 dB SNDR improvement can be achieved using such digital correction, while only 1∼2 dB with the commonly used mismatch-shaping technique.