The AD7894 is a fast， 14-bit ADC that operates from a single +5 V supply and is housed in a small 8-lead SOIC. The part contains a 5 μs successive approximation A/D converter， an onchip track/hold amplifier， an on-chip clock and a high speed serial interface. Output data from the AD7894 is provided via a high speed， serial interface port. This two-wire serial interface has a serial clock input and a serial data output with the external serial clock accessing the serial data from the part. In addition to the traditional dc accuracy specifications such as linearity， full-scale and offset errors， the AD7894 is also specified for dynamic performance parameters including harmonic distortion and signal-to-noise ratio. The part accepts an analog input range of ±10 V （AD7894-10）， ±2.5 V （AD7894-3）， 0 V to +2.5 V （AD7894-2）， and operates from a single +5 V supply consuming only 20 mW typical. The AD7894 features a high sampling rate mode and， for low power applications， a proprietary automatic power-down mode where the part automatically goes into power-down once conversion is complete and “wakes up” before the next conversion cycle. The part is available in a small outline IC （SOIC）.