GENERAL DESCRIPTION
The AD7195 is a low noise, complete analog front end for high precision measurement applications. It contains a low noise, 24-bit sigma-delta (Σ-Δ) analog-to-digital converter (ADC). The on-chip low noise gain stage means that signals of small amplitude can be interfaced directly to the ADC. The AD7195 contains ac excitation, which is used to remove dc-induced offsets from bridge sensors.

FEATURES
    AC or DC sensor excitation
    RMS noise: 8.5 nV at 4.7 Hz (gain = 128)
    16 noise-free bits at 2.4 kHz (gain = 128)
    Up to 22.5 noise-free bits (gain = 1)
    Offset drift: 5 nV/°C
    Gain drift: 1 ppm/°C
    Specified drift over time
    2 differential/4 pseudo differential input channels
    Automatic channel sequencer
    Programmable gain (1 to 128)
    Output data rate: 4.7 Hz to 4.8 kHz
    Internal or external clock
    Simultaneous 50 Hz/60 Hz rejection
    Power supply
        AVDD: 4.75 V to 5.25 V
        DVDD: 2.7 V to 5.25 V
    Current: 6 mA
    Temperature range: –40°C to +105°C
    Package: 32-lead LFCSP

INTERFACE
    3-wire serial
    SPI, QSPI™, MICROWIRE™, and DSP compatible
    Schmitt trigger on SCLK

APPLICATIONS
    Weigh scales
    Strain gage transducers
    Pressure measurement
    Temperature measurement
    Chromatography
    PLC/DCS analog input modules
    Data acquisition
    Medical and scientific instrumentation