Hi All,
Been a while since ive posted, but have picked up a little BLDC project again.
I have designed a PCB for this BLDC controller im making, but have put pull-down resistors on the hall sensor inputs instead of pull-ups, which are what I need for the particular motors I want to drive. Stupid mistake.
The manufacturers own BLDC controller uses 20k pull ups on their controllers, and I note the MSP430G2553's internal pull ups are 35k (20k-50k). If i were to just leave off the pull-downs on my PCB and use the internal pull ups, are they generally good enough to do the job?
Ive never used the MSP internal pull-ups/downs before so dont know what to expect.
This would save getting some new boards made, ill fix it with the next revision.
EDIT: Maybe an important bit of info. The hall sensors are 5V, so I have a voltage divider dropping the level to 3.3V. This is jointly acting as the pulldown. (5v through 270R to MSP430, pulled to ground via 470R).
Thanks!
Alec