SBOSAL3 February   2026 OPA4488

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information: OPA488
    5. 5.5 Thermal Information: OPA2488
    6. 5.6 Thermal Information: OPA4488
    7. 5.7 Electrical Characteristics
    8. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Input Common-Mode Range
      2. 6.3.2 Phase-Reversal Protection
      3. 6.3.3 Chopping Transients
      4. 6.3.4 EMI Rejection
      5. 6.3.5 Electrical Overstress
      6. 6.3.6 MUX-Friendly Inputs
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Basic Noise Calculations
    2. 7.2 Typical Applications
      1. 7.2.1 High-Side Current Sensing
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curve
      2. 7.2.2 Programmable Current Source
      3. 7.2.3 Programmable Current Source For A Grounded Load
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 PSpice® for TI
        2. 8.1.1.2 TINA-TI™ Simulation Software (Free Download)
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.2 Programmable Current Source

There are many applications that require a precise current source. Resistance temperature detectors (RTDs), for example, often require a precision current source to accurately measure temperature.Figure 7-5 shows a common configuration for a precision current source using the OPAx488. The circuit provides designers the ability to program the current for different use cases with a voltage source, such as a digital-to-analog converter (DAC).

OPA488 OPA2488 OPA4488 Howland Current Pump Figure 7-5 Howland Current Pump

The current is set by the differential input voltage, VIN+ − VIN−. Note that you can short one of the input voltages to control the current with a single ended signal as is the case here. The current is programmed according to Equation 4. Note that the maximum source and sink current is limited by the output drive capability of the amplifier. The Howland current pump is a great option for low level, very high precision current sources. The OPAx488 supply voltage of 48V provides the added benefit of a higher compliance voltage.

Equation 4. I L = V I N + - V I N - R S E T

To learn more about this circuit, visit the Analysis of Improved Howland Current Pump Configurations application report.