GENERAL DESCRIPTION
The AD7864 is a high speed, low power, 4-channel, simultaneous sampling 12-bit analog-to-digital converter (ADC) that operates from a single 5 V supply. The part contains a 1.65 μs successive approximation ADC, four track-and-hold amplifiers, a 2.5 V reference, an on-chip clock oscillator, signal conditioning circuitry, and a high speed parallel interface. The input signals on four channels sample simultaneously 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 (AD7864-2), and ±2.5 V (AD7864-3).

FEATURES
   High speed (1.65 μs) 12-bit ADC
   4 simultaneously sampled inputs
   4 track-and-hold amplifiers
      0.35 μs track-and-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 that allows
      Interfacing to 3 V processors
   Low power, 90 mW typical
   Power saving mode, 20 μW typical
   Overvoltage protection on analog inputs

APPLICATIONS
   AC motor control
   Uninterrupted power supplies
   Data acquisition systems
   Communications