Low Voltage, Low Power, 16-/24-Bit, Dual Sigma Delta ADC

The AD7719 is a complete analog front-end for low frequency measurement applications. It contains two high-resolution sigma delta ADCs, switchable matched excitation current sources, low-side power switches, digital I/O port and temperature sensor. The 24-bit main channel with PGA accepts fully differential, unipolar and bipolar input signal ranges from REFIN1/128 to REFIN1. Signals can be converted directly from a transducer without the need for signal conditioning. The 16-bit aux channel does not have a PGA and has an input signal range of REFIN2 or REFIN2/2.

* 2 Independent ADCs (16- and 24-Bit Resolution)

* Factory-Calibrated (Field Calibration Not Required)

* Output Settles in 1 Conversion Cycle (Single Conversion Mode)

* Programmable Gain Front End

* Simultaneous Sampling and Conversion of 2 Signal Sources

* Separate Reference Inputs for Each Channel

* Simultaneous 50 Hz and 60 Hz Rejection at 20 Hz Update Rate

ISOURCE SELECT™

* 24-Bit No Missing Codes—Main ADC

* 13-Bit p-p Resolution @ 20 Hz, 20 mV Range

* 18-Bit p-p Resolution @ 20 Hz, 2.56 V Range

INTERFACE

* 3-Wire Serial

* SPI®, QSPI™, MICROWIRE™, and DSP Compatible

* Schmitt Trigger on SCLK