The AD7896 is a fast， 12-bit ADC that operates from a single 2.7 V to 5.5 V supply and is housed in small 8-lead PDIP and 8-lead SOIC packages. The part contains an 8 μs successive approximation ADC， an on-chip track-and-hold amplifier， an on-chip clock， and a high speed serial interface. Output data from the AD7896 is provided via a high speed， serial interface port. This 2-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 AD7896 is also specified for dynamic performance parameters， including harmonic distortion and signal-to-noise ratio. The part accepts an analog input range of 0 V to VDD and operates from a single 2.7 V to 5.5 V supply， consuming only 9 mW typical. The VDD input is also used as the reference for the part so that no external reference is required. The AD7896 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， 8-lead， 0.3‘’ wide， plastic or hermetic dual-in-line package （PDIP） and in an 8-lead， small outline IC （SOIC）