SBOS936E November   2019  – August 2022 OPA182 , OPA2182 , OPA4182

PRODMIX  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information: OPA182
    5. 7.5 Thermal Information: OPA2182
    6. 7.6 Thermal Information: OPA4182
    7. 7.7 Electrical Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Phase-Reversal Protection
      2. 8.3.2 Input Bias Current Clock Feedthrough
      3. 8.3.3 EMI Rejection
      4. 8.3.4 Electrical Overstress
      5. 8.3.5 MUX-Friendly Inputs
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Strain Gauge Analog Linearization
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Rogowski Coil Integrator
      3. 9.2.3 System Examples
        1. 9.2.3.1 24-Bit, Delta-Sigma, Differential Load Cell or Strain Gauge Sensor Signal Conditioning
      4. 9.2.4 Programmable Power Supply
      5. 9.2.5 RTD Amplifier With Linearization
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 PSpice® for TI
        2. 10.1.1.2 TINA-TI™ Simulation Software (Free Download)
        3. 10.1.1.3 TI Reference Designs
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.2.3.1 24-Bit, Delta-Sigma, Differential Load Cell or Strain Gauge Sensor Signal Conditioning

The OPA2182 is used in a 24-bit, differential load cell or strain gauge sensor signal conditioning system alongside the ADS1225. The OPA2182 amplifier is configured in a two-amp instrumentation-amplifier (IA) configuration, and is band-limited to reduce noise and allow heavy capacitive drive. The load cell is powered by an excitation voltage (denoted VEX) of 5 V and provides a differential voltage proportional to force applied. The differential voltage can be quite small and both outputs are biased to VEX / 2.

In this example, the OPA2182 is employed here because of the excellent input offset voltage (0.45 µV) and input offset voltage drift (0.003 µV/°C), the low broadband noise (5.7 nV/√Hz) and zero-flicker noise, and excellent linearity and high input impedance. The two-amp IA configuration removes the dc bias and amplifies the differential signal of interest and drives the 24-bit, delta-sigma ADS1225 analog-to-digital converter (ADC) for acquisition and conversion. The ADS1225 features a 100-SPS data rate, single-cycle settling, and simple conversion control with a dedicated START pin.

GUID-20211217-SS0I-M7RD-HBTW-9X8PVP4KK53F-low.gif Figure 9-7 24-Bit Differential Load Cell or Strain Gauge Sensor Signal Conditioning Schematic