This test can be done with an external
15VDC power supply. Use the following
steps for this test:
- Power on the board with an external 15VDC power
supply from DC Jack J7
- Connect a DC power supply to two terminals of shunt resistor R67
- Set the DC power supply at constant voltage mode, and maximum current
- Enable output, then a surge output current flows
through R67.
- Adjust the power supply voltage and current output
- Make sure the surge current is high enough (>
6.5ADC) to trigger OCP.
Figure 4-14 shows the FAULT signal falls once current is
over 6A. The falling time is less than 2μs, which
can be fast enough to protect most of IGBT.
- CH1 (Blue): Fault signal at test point of #FAULT
- CH4 (Green): Current on R67