The AD7688 is a 16-bit， charge redistribution， successive approximation， analog-to-digital converter （ADC） that operates from a single 5 V power supply， VDD. It contains a low power， high speed， 16-bit sampling ADC with no missing codes， an internal conversion clock， and a versatile serial interface port. The part also contains a low noise， wide bandwidth， short aperture delay track-and-hold circuit. On the CNV rising edge， it samples the voltage difference between IN+ and IN? pins. The voltages on these pins usually swing in opposite phase between 0 V and REF. The reference voltage， REF， is applied externally and can be set up to the supply voltage. Its power scales linearly with throughput. The SPI-compatible serial interface also features the ability， using the SDI input， to daisy-chain several ADCs on a single， 3-wire bus and provides an optional BUSY indicator. It is compatible with 1.8 V， 2.5 V， 3 V， or 5 V logic， using the separate supply VIO. The AD7688 is housed in a 10-lead MSOP or a 10-lead LFCSP with operation specified from ?40°C to +85°C.