GENERAL DESCRIPTION
The AD7864 is a high speed, low power, 4-channel simultaneous sampling 12-bit A/D converter that operates from a single +5␣ V supply. The part contains a 1.65 µs successive approximation ADC, four track/hold amplifiers, 2.5 V reference, on-chip clock oscillator, signal conditioning circuitry and a high speed parallel interface. The input signals on four channels are sampled simultaneously, thus preserving the relative phase information of the signals on the four analog inputs. The part accepts analog input ranges of ±10␣ V, ±5 V (AD7864-1), 0 V to 2.5 V, 0 V to 5 V for AD7864-2 and ±2.5␣ V (AD7864-3).

FEATURES
   High Speed (1.65 μs) 12-Bit ADC
   Four Simultaneously Sampled Inputs
   Four Track/Hold Amplifiers
   0.35 μs Track/Hold Acquisition Time
   1.65 μs Conversion Time per Channel
   HW/SW Select of Channel Sequence for Conversion
   Single Supply Operation
   Selection of Input Ranges:
      ±10 V, ±5 V for AD7864-1
      ±2.5 V for AD7864-3
      0 V to 2.5 V, 0 V to 5 V for AD7864-2
   High Speed Parallel Interface Which Also Allows
      Interfacing to 3 V Processors
   Low Power, 90 mW Typ
   Power Saving Mode, 20 μW Typ
   Overvoltage Protection on Analog Inputs

APPLICATIONS
   AC Motor Control
   Uninterrupted Power Supplies
   Data Acquisition Systems
   Communications