Electrical – BLDC control using driver with external MOSFETs


I would like to be able to control various kinds of sensorless brushless DC motors for robotics. Hobby ESCs are everywhere but I'd like to drive motors with a simple PWM output from a central controller without having to create a servo-like control pulse. First because it's marginally easier to do in software. Second because it would then be possible to replace existing brushed DC motors in existing equipment without modification.

I have found the MTD6501G which looks just fine and I see many people successfully driving dismantled hard drives and fan motors with it. However it can supply only 0.8A.

Another is DRV8301 – more complicated, more expensive, more external components required.

Would it be possible to use the MTD6501G with motors requiring more current by using cheap external drivers like MJE2955 on each of the phase outputs?

Best Answer

Thanks to those who reviewed and commented. Looks like MTD6501G is not going to work because using it to drive external silicon to increase power handling would remove the feedback from the windings that the device requires.

DRV8301 or similar does seem to be the only option if you must build your own speed controller.

The Vedder ESC is what I will probably buy for some immediate uses, and think further about experimenting with DRV8301 or similar devices - but it is going to need a reflow oven to mount so that is another challenge to overcome.