DRV8833: Pin VM voltage high issue

Cooper Zhang1

Part Number: DRV8833
Other Parts Discussed in Thread: TPS61085

Dear:

please help me check DRV8833 pin12 VM maximum voltage is 30V(multimeter test) when motor is running, customer find the motor is faster, the voltage is bigger; we check the datasheet VM Vmax is 11.8V，

they want to know the condition is normal operation or not ?

the schematic is as attached.

yuntai2103sch.pdf

over 3 years ago

0 Wang5577 over 3 years ago

TI__Guru 56650 points

Cooper,

What is the input source voltage when the motor is running?

"when motor is running, customer find the motor is faster, the voltage is bigger"

Is the motor driving by the DRV8833 or other source? Would you share any test waveform?

Regards,

Wang

0 Cooper Zhang1 over 3 years ago in reply to Wang5577

Expert 2190 points

Dear

I have shared your schematic, dvr8833 supply power is tps61085 boost 9V to VM

0 Cooper Zhang1 over 3 years ago in reply to Wang5577

Expert 2190 points

dear:

no input source, the power closed, using manually rotate the motor, reverse current to VM point, the voltage is 30V around，I want to know how to deal with it, I want to add TVS to be stable the VM source

0 Wang5577 over 3 years ago in reply to Cooper Zhang1

TI__Guru 56650 points

Cooper,

Ok, the 30V is not generated by the front end boost converter.

When manually rotate the motor, the motor runs like a generator which generate 30V on the motor terminal.

Yes. The TVS can absorb the extra energy which is generated by the motor. Or, you can add a machinal switch/damper to block the motor free running after power close.

Regards,

Wang Li

Motor drivers

Motor drivers forum

DRV8833: Pin VM voltage high issue