GENERAL DESCRIPTION
The AD7719 is a complete analog front end for low frequency measurement applications. It contains two high resolution Σ-∆ ADCs, switchable matched excitation current sources, low-side power switches, digital I/O port, and temperature sensor.
FEATURES
HIGH RESOLUTION Σ-Δ ADCs
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
POWER
Specified for Single 3 V and 5 V Operation
Normal: 1.5 mA Typ @ 3 V
Power-Down: 10 μA (32 kHz Crystal Running)
ON-CHIP FUNCTIONS
Rail-Rail Input Buffer and PGA
4-Bit Digital I/O Port
On-Chip Temperature Sensor
Dual Switchable Excitation Current Sources
Low-Side Power Switches
Reference Detect Circuit
APPLICATIONS
Sensor Measurement
Temperature Measurement
Pressure Measurement
Weigh Scales
Portable Instrumentation
4 to 20 mA Transmitters