Hello Luong,
Healthy & successful New Year!
The most likely fault is either a deadtime fault (DEADT bit in the STATUS2 register) based on the PWM signal, or a desaturation fault (DESAT in the STATUS1 register) if the GD3100 has been configured that way.
If you have SPI capability, you can read the STATUS1 and STATUS2 registers to find out which error is present.
Deadtime fault:
- To provide sufficient deadtime, use the integrated deadtime on your MCU providing the PWM pulse train. If this isn't the case you can add an asymmetric RC delay circuit with an antiparallel diode to acquire "fast" turn-off and "slow" turn-on behavior to satisfy the GD3100 deadtime detection.
- If you have the ability to configure the gate driver by SPI, you can mask the deadtime fault (DTFLTM = 0 in MSLK2 register) or set the deadtime value to match the PWM signal provided (use DEADT[3:0] in the CONFIG5 register) to eliminate this.
Desaturation fault:
Can occur without a power device connected, due to the open collector pin: the DESAT pin immediately charges and trips and the gate is shut down. This is a severe fault with a power device attached, so the gate is latched off. You would see no gate movement in response to the PWM input signal on a scope, and zero difference in the supply current between PWM going vs. PWM off.
- A hardware workaround for this, would be to connect a wire short from the collector pin to the emitter pin (no connection to the gate pin) until you connect a power device.
- In software, you could disable the DESAT mode bit (in the MODE1 register) until you can attach the power device. By default this mode is already disabled.
BR, Tomas
