DRV8870: MOTOR Can not workable

Hi Angus,

Have you taken a look at the the power supply voltage (VM)? If the motor tries to draw more than 2A (power supply limit), it will cause the power supply voltage to drop which may cause an under-voltage lockout fault (UVLO). A UVLO fault will disable the outputs until VM increases to operating limit.

Are you using your own board design or the DRV8870EVM?

Hi Angus,

Any updates from your side?

Hi Pablo

I use the power supply & motor can work fine.

& this circuit is still not workable, I'll check it again. Thanks for your help

BR,Angus

Hi Angus,

So the issue with the motor is fixed by the power supply? You mention the circuit is still not workable so i want to confirm if you are able to spin the motor now.

Hi Pablo

Pls check picture. thanks

To connect power supply directly that motor is workable.

but add drv8870 is not workable, fyi.

Hi Angus,

Understood. In that case we know the power supply and the motor seem to be working properly.

For the next test, can you disconnect the motor from the driver and measure the voltage of the following pins:

• IN1, IN2
• VREF
• VM
• OUT1, OUT2
• ISEN

Hi Pablo

picture, fyi.

1) Out1 & Out2 connect to volt meter is 7.5V

2) Three pin connected together to system GND ( GND/IN2/ISEN )

3) Vref & IN1 connected together is about 2.84V  (7.5 X( 10/10+15 )=~ 2.84V) , I use 2 resistors to divide the 7.5V volt)

4) VM to Gnd is 7.5V

BR,Angus