GENERAL DESCRIPTION

The AD7790 is a low power, complete analog front end for low frequency measurement applications. It contains a low noise 16-bit ∑-Δ ADC with one differential input that can be buffered or unbuffered along with a digital PGA, which allows gains of 1, 2, 4, and 8.

FEATURES

Power

  Supply: 2.5 V to 5.25 V operation

  Normal: 75 μA maximum

  Power-down: 1 μA maximum

RMS noise: 1.1 μV at 9.5 Hz update rate

16-bit p-p resolution

Integral nonlinearity: 3.5 ppm typical

Simultaneous 50 Hz and 60 Hz rejection

Internal clock oscillator

Programmable gain amplifier

Rail-to-rail input buffer

VDD monitor channel

Temperature range: –40°C to +105°C

10-lead MSOP

INTERFACE

3-wire serial

SPI®, QSPI™, MICROWIRE™, and DSP compatible

Schmitt trigger on SCLK

APPLICATIONS

Smart transmitters

Battery applications

Portable instrumentation

Sensor measurement

Temperature measurement

Pressure measurement

Weigh scales

4 to 20 mA loops