SLUUD68 December   2024

 

  1.   1
  2.   Abstract
  3. 13
  4. 1General TI High Voltage Evaluation User Safety Guidelines
  5. 2Module Compatibility
    1. 2.1 Supported Wolfspeed Modules and Evaluation Platforms
  6. 3System Overview and Functions
    1. 3.1 Features
    2. 3.2 Specifications
    3. 3.3 PCB Pinout
    4. 3.4 Device Information
      1. 3.4.1 Primary-Side Power
      2. 3.4.2 Primary-Side I/O and Diagnostics
      3. 3.4.3 Secondary-Side Bias Supply
      4. 3.4.4 Output Stage Gate Loop
      5. 3.4.5 Short-Circuit Detection - DESAT
  7. 4Using the EVM
    1. 4.1 Equipment List
    2. 4.2 Test Setups and Procedures
      1. 4.2.1 Power-On and Bias Supply Check
      2. 4.2.2 Output Switching
  8. 5EVM Example Measurements
    1. 5.1 DESAT Functionality Testing
  9. 6EVM Tuning
    1. 6.1 Adjust Power Supplies
      1. 6.1.1 Adjust Only VDD Bias Supply
      2. 6.1.2 Adjust VDD and VEE Bias Supplies Simultaneously
      3. 6.1.3 Switch to Unipolar Bias Supply
      4. 6.1.4 Bypass VDD LDO
    2. 6.2 Adjust Drive Strength
    3. 6.3 Adjust Soft Turn-off Strength
  10. 7Hardware Design Files
    1. 7.1 Schematics
    2. 7.2 PCB Layouts
    3. 7.3 Bill of Materials (BOM)
  11. 8Additional Information
    1. 8.1 Trademarks
  12. 9Revision History

3.4.3 Secondary-Side Bias Supply

The secondary-side power supply block fulfills the following functions:

  • Converts the +12-V input voltage to +20-V/-5.5-V bipolar bias voltage supply for the secondary side of the gate drivers. Each gate driver has its own bias supply. This is achieved by using one LM5185-Q1 flyback controller and one YA8864-BLD transformer for each gate driver.
  • Reduces the noise of the positive secondary side supply voltage by using a TPS7A4901 LDO.
    • This LDO can also be bypassed by following the instructions in Section 6.1.4
UCC2189X5YQEVM-096 Secondary-Side Bias Supply Figure 3-5 Secondary-Side Bias Supply