SBOS830I September   2017  – October 2021 OPA189 , OPA2189 , OPA4189

PRODUCTION DATA  

  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: OPA189
    5. 7.5 Thermal Information: OPA2189
    6. 7.6 Thermal Information: OPA4189
    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 Operating Characteristics
      2. 8.3.2 Phase-Reversal Protection
      3. 8.3.3 Input Bias Current Clock Feedthrough
      4. 8.3.4 EMI Rejection
      5. 8.3.5 EMIRR +IN Test Configuration
      6. 8.3.6 Electrical Overstress
      7. 8.3.7 MUX-Friendly Inputs
      8. 8.3.8 Noise Performance
      9. 8.3.9 Basic Noise Calculations
    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 25-kHz Low-Pass Filter
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Discrete INA + Attenuation for ADC With 3.3-V Supply
      3. 9.2.3 Bridge Amplifier
      4. 9.2.4 Low-Side Current Monitor
      5. 9.2.5 Programmable Power Supply
      6. 9.2.6 RTD Amplifier With Linearization
    3. 9.3 System Examples
      1. 9.3.1 24-Bit, Delta-Sigma, Differential Load Cell or Strain Gauge Sensor Signal Conditioning
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
        1. 12.1.1.1 TINA-TI™ Simulation Software (Free Download)
        2. 12.1.1.2 TI Precision Designs
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.1.2 Detailed Design Procedure

The infinite-gain multiple-feedback circuit for a low-pass network function is shown in Figure 9-1. Use Equation 1 to calculate the voltage transfer function.

Equation 1. GUID-67985394-52F1-4802-919B-43010C6C154E-low.gif

This circuit produces a signal inversion. For this circuit, the gain at dc and the low-pass cutoff frequency are calculated by Equation 2:

Equation 2. GUID-329BE6C0-9F97-480C-820C-A7EC31D204AE-low.gif

Software tools are readily available to simplify filter design. WEBENCH® Filter Designer is a simple, powerful, and easy-to-use active filter design program. The WEBENCH® Filter Designer lets the user create optimized filter designs using a selection of TI operational amplifiers and passive components from TI's vendor partners.

Available as a web based tool from the WEBENCH Design Center, WEBENCH Filter Designer allows board-level designers to create, optimize, and simulate complete multistage active filter solutions within minutes.