SLUUCR5A december   2022  – june 2023 LM74900-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 EVM Features
    2. 1.2 EVM Applications
  5. 2Description
  6. 3Schematic
  7. 4General Configurations
    1. 4.1 Physical Access
    2. 4.2 Test Equipment and Setup
      1. 4.2.1 Power Supplies
      2. 4.2.2 Meters
      3. 4.2.3 Oscilloscope
      4. 4.2.4 Loads
  8. 5Test Setup and Procedures
    1. 5.1 Power-Up and Power-Down With EN Control
    2. 5.2 Input Overvoltage Test
    3. 5.3 Overcurrent Protection Test
    4. 5.4 Output Hot-Short Test
  9. 6EVAL Board Assembly Drawings
    1. 6.1 PCB Drawings
  10. 7Bill of Materials (BOM)
  11. 8Revision History

5.1 Power-Up and Power-Down With EN Control

Use the following instructions to capture the precharging current profile.

  1. Initially connect the EN pin to GND by setting J5 jumper at 2-3 position.
  2. Set the input supply voltage VIN to 12 V and current limit of 10 A.
  3. Turn ON the power supply.
  4. Enable the LM74900-Q1 device by connecting EN pin to C. Change the J5 jumper setting to 1-2.
  5. Observe the start-up profile of charge pump voltage (VCAP – VVS), output voltage, HGATE, and DGATE.
  6. Disable the LM74900-Q1 device by connecting EN pin to GND. Change the J5 jumper setting to 2-3.
  7. Observe the shutdown profile of charge pump voltage (VCAP – VVS), output voltage, HGATE, and DGATE.
Figure 5-2 shows an example of power-up with EN profile captured on the LM74900Q1EVM evaluation board.
GUID-20221128-SS0I-LCMN-WQNJ-6TB8G03HWCHC-low.png Figure 5-2 LM74900-Q1 Start-Up With EN - Output Voltage and Input Current Profile
GUID-20221128-SS0I-MXJB-S9FK-L2TJT5H3N9WC-low.png Figure 5-3 LM74900-Q1 Start-Up With EN - Charge Pump and Output Voltage Profile
GUID-20221128-SS0I-3SZV-PR9Z-SMKSMFSB3DVQ-low.png Figure 5-4 LM74900-Q1 Shutdown With EN - HGATE and Output Voltage Profile
GUID-20221128-SS0I-CWWF-3W4B-5F482DWPPTQH-low.png Figure 5-5 LM74900-Q1 Shutdown With EN - DGATE and Output Voltage Profile