The functionally complete, easy-to-use ADS-CCD1201 is a 12-bit, 1.2MHz Sampling A/D Converter whose performance and production testing have been optimized for use in electronic imaging applications, particularly those employing charge coupled devices (CCD's) as their photodetectors. The ADS-CCD1201 delivers the lowest noise (400Vrms) and the best differential nonlinearity error (0.35LSB max.) of any commercially available 12-bit A/D in its speed class. It can respond to full scale input steps (from empty to full well) with less than a single count of error, and its input is immune to overvoltages that may occur due to blooming.