The AD7854/AD7854L is a high speed， low power， 12-bit ADC that operates from a single 3 V or 5 V power supply， the AD7854 being optimized for speed and the AD7854L for low power. The ADC powers up with a set of default conditions at which time it can be operated as a read-only ADC. The ADC contains self-calibration and system calibration options to ensure accurate operation over time and temperature and has a number of power-down options for low power applications. The AD7854 is capable of 200 kHz throughput rate while the AD7854L is capable of 100 kHz throughput rate. The input track-and-hold acquires a signal in 500 ns and features a pseudodifferential sampling scheme. The AD7854 and AD7854L input voltage range is 0 to VREF （unipolar） and –VREF/2 to +VREF/2， centered at VREF/2 （bipolar）。 The coding is straight binary in unipolar mode and twos complement in bipolar mode. Input signal range is to the supply and the part is capable of converting full-power signals to 100 kHz. CMOS construction ensures low power dissipation of typically 5.4 mW for normal operation and 3.6 μW in power-down mode. The part is available in 28-lead， 0.6 inch wide dual-in-line package （DIP）， 28-lead small outline （SOIC） and 28-lead small shrink outline （SSOP） packages.