The AD7933/AD7934 are 10-bit and 12-bit， high speed， low power， successive approximation （SAR） analog-to-digital converters （ADCs）。 The parts operate from a single 2.7 V to 5.25 V power supply and feature throughput rates up to 1.5 MSPS. The parts contain a low noise， wide bandwidth， differential trackand-hold amplifier that handles input frequencies up to 50 MHz. The AD7933/AD7934 feature four analog input channels with a channel sequencer that allows a preprogrammed selection of channels to be sequentially converted. These parts can accept either single-ended， fully differential， or pseudo differential analog inputs. The conversion process and data acquisition are controlled using standard control inputs that allow for easy interfacing to microprocessors and DSPs. The input signal is sampled on the falling edge of CONVST， and the conversion is also initiated at this point. The AD7933/AD7934 has an accurate on-chip 2.5 V reference that is used as the reference source for the analog-to-digital conversion. Alternatively， this pin can be overdriven to provide an external reference.