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