GENERAL DESCRIPTION

The AD7711 is a complete analog front end for low frequency measurement applications. The device accepts low level signals directly from a transducer and outputs a serial digital word. It employs a Σ-Δ conversion technique to realize up to 24 bits of no missing codes performance. The input signal is applied to a proprietary programmable gain front end based around an analog modulator.

FEATURES

Charge-Balancing ADC

24 Bits, No Missing Codes

±0.0015 Nonlinearity

2-Channel Programmable Gain Front End

Gains from 1 to 128

1 Differential Input

1 Single-Ended Input

Low-Pass Filter with Programmable Filter Cutoffs

Ability to Read/Write Calibration Coefficients

RTD Excitation Current Sources

Bidirectional Microcontroller Serial Interface

Internal/External Reference Option

Single- or Dual-Supply Operation

Low Power (25 mW typ) with Power-Down Mode

(7 mW typ)

APPLICATIONS

RTD Transducers

Process Control

Smart Transmitters

Portable Industrial Instruments