SLVSIS7 October   2026 OPA2986

ADVMIX  

  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 for OPA986
    5. 5.5 Thermal Information for OPA2986
    6. 5.6 Thermal Information for OPA4986
    7. 5.7 Electrical Characteristics for VS = 8V to 48V
    8. 5.8 Electrical Characteristics for VS = 4.5V to 8V
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Mux-Friendly Inputs
      2. 6.3.2 Thermal Protection
      3. 6.3.3 Overload Recovery
      4. 6.3.4 Slew Rate
      5. 6.3.5 Full-Power Bandwidth Improved
      6. 6.3.6 e-Trim
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 2nd Order Low Pass Filter
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curves
      2. 7.2.2 High-Side Current Sense
      3. 7.2.3 MDAC Output Gain and Buffer
    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 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.2.2 High-Side Current Sense

The OPAx986 enables high voltage current sense measurements. High-side voltage measurements of 48V can be easily implemented using the OPAx986. The voltage capability is proportional to the gain of the sense circuit and the input common-mode range of the amplifier. Figure 7-4 shows the OPA986 configured for a 36V battery high side current measurement and a gain of 40V/V to generate a 3V full-scale output. A high precision amplifier gain stage is not needed in this design.

Make the input resistors large enough to avoid any loading related errors. The low input bias current of the OPAx986 allows for the use of larger resistors when compared to other power amplifiers and is not a major contribution to the total error in this application. Special consideration of input bias current, thermal noise, and input common-mode range is warranted when choosing resistors for this design.

OPA986 OPA2986 OPA4986 36V Battery High-Side Current Sense Figure 7-4 36V Battery High-Side Current Sense

Consider using the RES21A matched resistor pair to achieve high common-mode rejection ratio (CMRR) in a ready to use package.