METHOD FOR SUCCESSIVE APPROXIMATION A/D CONVERSION

A method of successive approximation A/D conversion employing an N bit internal D/A converter and an N bit SAR is provided wherein the first X bits are approximated to within less than the desired accuracy for N bit successive approximation while the last Y bits are approximated to within at least the desired accuracy for N bit successive approximation. After the Xth bit approximation, the A/D converter may be allowed sufficient time to settle to within the desired accuracy for N bit approximation during an error correction stage which increments or decrements the digital signal for the first X bits.