GD3162 gate driver SC fault

[Akshat_VE02376]

Hi NXP,
What could be the reason that INTB is going to 2.5V from 5V in the case of a short circuit fault ? Can there be any causes in SW? Any possibility ?

[ErikaC · Accepted solution]

Hello,

Is the INTB pin directly connected to the microcontroller? Please note that the INTB pin has an internal passive pull-up to VDD, and INTB reports faults with an active low signal (logic 0 indicates a fault). According to the datasheet, the INTB pin should indeed be connected directly to the microcontroller.

Could you confirm whether, when disconnecting the microcontroller from the INTB pin, the voltage remains at 2.5V in the event of a fault?

[Akshat_VE02376]

Hi, FYI,
in our project, all the INTB pins are connected to one pin of the micro so that if any one of the gate drivers (6 gate (RH, YH, BH and RL, YL, BL) for 3 phase motor) encounters a fault, the PWM is cut off for all.
In the attached image you can see that ISENSE pin of the R-L gate driver is supposed to detect phase over current cut off through SC fault and ISEN of Y-L gate driver is supposed to detect DC over current cut off through SC fault.
In our case whenever ISEN of YL detects DC bus over current cut off, in that case INTB is going to 2.5V and when phase over current cut off occurs, then INTB is further transitioning from 2.5 to 0.
I've noted your point to disconnect INTB from micro and check the signal again.

[ErikaC]

Hello

Could you please let me know the result? Additionally, would you be able to test the INTB connected directly to the microcontroller?

[Akshat_VE02376]

And also, INTB before connecting to micro is externally given a pull-up to 5V through a 10K resistor