TIDUEH2C April   2021  – September 2022

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 OPA365-Q1 (50 MHz)
      2. 2.3.2 OPA607-Q1 (50 MHz)
      3. 2.3.3 OPA836 (same as OPA2836-Q1) (205 MHz)
      4. 2.3.4 OPA863 (50 MHz)
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
      1.      19
    3. 3.3 Test Results
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks
  10. 5About the Author
  11. 6Revision History

Description

This reference design demonstrates the benefits of wide gain bandwidth product (GBWP) amplifiers in low-side current sensing applications with fast-switching frequencies. This design multiplexes the OPA365-Q1, OPA836, OPA863, and OPA607-Q1 to monitor a low-side 1-mΩ shunt resistor. Example applications include single-shunt low-side sensing for motors, high-current and high-speed motors, high-frequency switching power supplies, on-board chargers (OBC), and fault-detection hardware. The featured high-speed amplifiers are configured in a gain of 33-V/V, for wide-dynamic-range current monitoring and accurately sensing transients above ±50-A. In this configuration, each amplifier can settle a large-signal step-response within 0.5-μs and accurately drive the typical 250-ns acquisition period of a 2 MSPS, 12-bit internal ADC used in most TI microcontrollers for motor control. These enhancements are available at a similar cost and power consumption as lower-bandwidth devices.