Description

The AD7705BRUZ is an Analog to Digital Converter (ADC) designed for low-frequency measurement applications. It is a programmable, two-channel front-end device that can accept low-level input signals directly from a transducer and produce an output in serial digital format. The device uses a Σ-Δ conversion technique, providing up to 16 bits of no missing code performance. It features a proprietary, programmable-gain front end based around an analog modulator. The modulator output is then processed by an on-chip digital filter to provide accurate results.

Specifications and Features

• Maximum Resolution: 16 bits
• Number of Channels: 2
• Input Range: 0 mV to 20 mV through 0 V to 2.5 V
• Input Type:
  • AD7705: Fully Differential Input Channels
  • AD7706: Pseudo Differential Input Channels
• Reference Input: Differential
• Serial Interface: 3-wire
• Power Dissipation: 1 mW maximum @ 3 V
• Standby Current: 8 μA maximum
• Package Types: 16-lead PDIP, 16-lead SOIC, and 16-lead TSSOP packages

Application Scenarios

The AD7705BRUZ is ideal for use in smart, microcontroller, or DSP-based systems. The device features a serial interface that can be configured for 3-wire operation. Gain settings, signal polarity, and update rate selection can be configured in software using the input serial port. The parts contain self-calibration and system calibration options to eliminate gain and offset errors on the part itself or in the system. The device is suitable for a broad range of low-frequency measurement applications.

Comparison

• Provides accurate and reliable results
• Uses Σ-Δ conversion technique to achieve up to 16 bits of no missing code performance
• Features a programmable-gain front end that supports gains from 1 to 128
• Low power dissipation

• May not be suitable for high-frequency applications
• Only supports up to two input channels