I'm testing the ISO5852S driver to replace the equivalent NCD57000 (onsemi) in a 6kw IGBT buck converter, with a frequency switching of 40kHz.
When i apply the pwm signal to the input, the output always stays at VEE2.
I state that with NCD57000 (pin-out compatible) I don't have this problem (same board, same conditions)
I summarize the tests I have carried out.
1) I installed the ISO5852S driver in a "virgin" pcb board and applied a pwm with the oscilloscope signal generator. in this case I have no problems.
2) I installed the component in the pcb board also populated with other components (microcontroller, logic gates, etc..). If I apply a signal to the driver input, the output always remains at -5V (VEE2) and there is no switching, even though the input signal is correct.
NOTE: if I install NCD57000 in this same pcb board, this works correctly.
Since things "do not add up" I proceeded by doing these three tests:
1) Disconnected microcontroller output and connected signal generator in place of the microcontroller output (outl schematic point), in doing so the driver does not work.
2) Microcontroller output connected directly to driver input bypassing the logic gates, doing so does not work.
3) Removed the NOR logic gate and directly connected the signal generator (point DRV OUTL schematic) to the driver input, this to put me in conditions similar to the test ones on the "virgin" pcb board. By doing this, the driver works correctly.
I really can't explain this phenomenon, as in all cases I measure the IN+, IN-, FLT, RDY, RST signal of the driver correctly.
It seems to be a problem due to the type of source that generates the pwm and/or the presence of components between the source and the driver input. Could it be a problem related to the current that the source that generates the pwm can deliver?
