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