GENERAL DESCRIPTION

The AD7796/AD7797 are complete, analog front ends for high precision, bridge sensor applications such as weigh scales. The AD7796/AD7797 contain a Σ-Δ ADC capable of 16-/24-bit resolution, respectively. The on-chip instrumentation amplifier has a fixed gain of 128, allowing small amplitude signals such as those from bridge sensors to be directly interfaced to the ADC.

FEATURES

RMS noise: 65 nV

Instrumentation amp

Temperature sensor

Internal clock oscillator

Simultaneous 50 Hz/60 Hz rejection

Update rate: 4.17 Hz to 123 Hz

Current: 250 μA typ

Power-down: 1 μA

Power supply: 2.7 V to 5.25 V

–40°C to +85°C temperature range

Independent interface power supply

16-lead TSSOP

INTERFACE

3-wire serial

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

Schmitt trigger on SCLK

APPLICATIONS

Weigh scales

Strain gages

Industrial process control

Instrumentation

Portable instrumentation