Define Successive Approximation Digital to Analog Converter?
Successive approximation ADCs transform analog signals to digital data by comparing the incoming analog signal along with a reconstructed guess from a DAC that sequentially doubles every guess on every clock cycle.
The feedback in a Sigma Delta ADC is made from averaging a 1-bit DAC sampled at an extremely high rate. Sigma Delta ADCs are extensively used due to their reasonable pricing and digital reliability.