The AD7641 is an 18-bit， 2 MSPS， charge redistribution SAR， fully differential， analog-to-digital converter （ADC） that operates from a single 2.5 V power supply. The part contains a high speed， 18-bit sampling ADC， an internal conversion clock， an internal reference （and buffer）， error correction circuits， and both serial and parallel system interface ports. It features two very high sampling rate modes （wideband warp and warp） and a fast mode （normal） for asynchronous rate applications. The AD7641 is hardware factory calibrated and tested to ensure ac parameters， such as signal-to-noise ratio （SNR）， in addition to the more traditional dc parameters of gain， offset， and linearity. The AD7641 is available in Pb-free only packages with operation specified from ?40°C to +85°C.