I bought a GaN driver (ADUM4121) from ADI company for GaN short circuit test.
Figure 1 in the attachment is the schematic diagram of short circuit test. The principle of the whole short circuit is: first supply power to the left and right of adum4121 driver; then use high voltage source to charge the 200uf DC capacitor; finally use function generator to control the PWM driving the left side to realize the output of driving the right side Vout.
Figure 2 in the attachment is the circuit diagram I built (PCB is made according to the circuit diagram).
Figure 3 in the attachment is the problem I found during the short circuit test: when the voltage supplied by the high voltage source exceeds 100V, the PWM waveform channel 4 (2us length) on the left side of the drive can be normally turned off; however, the Vout signal (channel 3) on the right side of the drive can only be turned off after several hundred us.
In my opinion, under normal conditions, the left PWM should be turned off, and the right Vout signal should also be turned off. PWM and Vout will not have such a large delay.