GENERAL DESCRIPTION
The AD7712 is a complete analog front end for low frequency measurement applications. The device has two analog input channels and accepts either low level signals directly from a transducer or high level (±4
VREF) signals, and outputs a serial digital word. It employs a sigma-delta conversion technique to realize up to 24 bits of no missing codes performance. The low level input signal is applied to a proprietary programmable gain front end based around an analog modulator. The high level analog input is attenuated before being applied to the same modulator. The modulator output is processed by an on-chip digital filter. The first notch of this digital filter can be programmed via the on-chip control register, allowing adjustment of the filter cutoff and settling time.

FEATURES
    Charge Balancing ADC
        24 Bits No Missing Codes
        ±0.0015% Nonlinearity
    High Level and Low Level Analog Input Channels
    Programmable Gain for Both Inputs Gains from 1 to 128 Differential Input for Low Level Channel
    Low-Pass Filter with Programmable Filter Cutoffs
    Ability to Read/Write Calibration Coefficients
    Bidirectional Microcontroller Serial Interface
    Internal/External Reference Option
    Single- or Dual-Supply Operation
    Low Power (25 mW typ) with Power-Down Mode (100 μW typ)

APPLICATIONS
    Process Control
    Smart Transmitters
    Portable Industrial Instruments