The AD7663 is a 16-bit， 250 kSPS， charge redistribution SAR， analog-to-digital converter that operates from a single 5 V power supply. It contains a high speed 16-bit sampling ADC， a resistor input scaler that allows various input ranges， an internal conversion clock， error correction circuits， and both serial and parallel system interface ports. The AD7663 is hardware factory-calibrated and is comprehensively tested to ensure such ac parameters as signal-to-noise ratio （SNR） and total harmonic distortion （THD）， in addition to the more traditional dc parameters of gain， offset， and linearity. It is fabricated using Analog Devices’ high performance， 0.6 micron CMOS process and is available in a 48-lead LQFP and a tiny 48-lead LFCSP with operation specified from –40°C to +85°C.