GENERAL DESCRIPTION

The AD7782 is a complete analog front end for low-frequency measurement applications. The 24-bit sigma-delta ADC contains two fully differential analog input channels that can be configured with a gain of 1 or 16 allowing full-scale input signal ranges of ±2.56 V or ± 160 mV from a +2.5 V differential reference input.

FEATURES

2-Channel, 24-Bit Σ-Δ ADC

Pin Configurable (No Programmable Registers)

Pin Selectable Input Channels

Pin Programmable Input Ranges (±2.56 V or ±160 mV)

Fixed 19.79 Hz Update Rate

Simultaneous 50 Hz and 60 Hz Rejection

24-Bit No Missing Codes

18.5-Bit p-p Resolution (±2.56 V Range)

16.5-Bit p-p Resolution (±160 mV Range)

INTERFACE

Master or Slave Mode of Operation

Slave Mode

3-Wire Serial

SPI™, QSPI™, MICROWIRE™, and DSP-Compatible

Schmitt Trigger on SCLK

POWER

Specified for Single 3 V and 5 V Operation

Normal: 1.3 mA @ 3 V

Power-Down: 9 μA

ON-CHIP FUNCTIONS

Rail-Rail Input Buffer and PGA

APPLICATIONS

Sensor Measurement

Industrial Process Control

Temperature Measurement

Pressure Measurements

Weigh Scales

Portable Instrumentation