The ADS7818 is a 12-bit sampling analog-to-digital converter (A/D) complete with sample/hold, internal 2.5V reference, and synchronous serial interface. Typical power dissipation is 11mW at a 500kHz throughput rate. The device can be placed into a power down mode which reduces dissipation to just 2.5mW. The input range is zero to two times the reference voltage, and the internal reference can be overdriven by an external voltage.