DRV8323R: Control a brushless motor directly without MCU

Hi Team,

I'm posting this in behalf of the customer. 

I read many different questions about this driver (8320 family) but I wanted to ask related question on the E2E forum.

https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1026186/drv8323r-drv8323-to-control-high-speed-sensorless-bldc-motor

I would like to ask a particular question about your 8320 gate driver chips

The final goal of my design is to be able to control a brushless motor directly without MCU

So by reading the datasheet I've seen that the 8320 family gate drivers can be controlled in various way, and probably the best way to control them in the "stand alone" manner is by using a 1xPWM input configuration

In order to control it MCUlessly, we need to use hall sensors for position feedback of the brushless motor

I would like to know what is the practical limit of eRPMs of the brushless motor using this kind of hall position feed back commutation procedure. The motors I will need to control are extremely high rpm (>100,000 rpms with 9 pole magnets)

Basically the final result I was looking for was a system that spins a brushless motor only by supplying a constant input voltage to the gate driver and mosfets. In other words it would be controlled as if it was a brushed dc motor, where low voltage spins it slowly, and by increasing the voltage you also increase the speed of the motor. Obviously there has to be a PWM input signal to the gate drive that is fixed on 99-100% duty cycle

The system should be able to turn on instantaneously (1ms of the on time required for the gate driver to turn on, as long as the 100% PWM duty cycle input doesn't put the gate driver in protection mode)

Yes absolutely. I chose that 8320 gate driver, but if you think that there are better products/solutions for my system please consider them.

Best regards,

Jonathan