Hello everyone,
I am working on a desing with DRV8301.
It works fine but I experience the circuit is warmer than expected.
The plan is to drive 3 or more Mosfets in parallel.
I have more prototypes and I measured the current to PVDD.
When I use 6pcs (1 in parallel) CSD18533Q5A with 29nC @ 10V with 45kHz and 8.3V I expect Igate = 29e-9 * 6 * 45e3 = 8mA
The supply current is 22mA. I'd expect slightly more than 8mA, but 22mA is too much (though still bellow 30mA maximum for DRV8301)
When I use 18pcs IRQF (59nC @10V), the current is much larger - 90mA, though theoretical one is Igate = 59e-9*18*45e3 = 50mA
I measured worse (150mA @45kHz) values for 6pcs of NTMFS4935NT1G (50nC @10V) but was not able to reproduce it other day with other day (then it was 30mA - still out of expected 14mA ). This actually initiated the investigation.
1. Can a "rough" soldering (hot air 400 degC) affect the transistor total charge in some way?
2. Can a variation of transistor parameters contribute to these results so significantly?
3. How much of the supply current goes to "Igate" and how much is consumed "internally".
4. Is 30mA a value that must not be exceeded or is it somehow limited internally?
5. I there anything else that should be taken into account and I might be omitting it?
Note: Constant 56mA supplying buck converter have been substracted from the real measurements.
Thank you in advance