DRV8837: VM and Vcc gets internal short

Velmurugan Ekambanathan

Part Number: DRV8837

Hi,

We are using this DRV8837 device to control the DC motor, we have assembled 5 board initially all worked well, but while dong the functional testing 3 device failed, we see the Vm voltage at the Vcc pin, and this in turn make other device to fail that are connected in the Vcc Rail.We follow the reference design given in the datasheet, with over voltage protection at the VM pin.

Our products operates with a 6V Lead Acid Battery. Motor Rated voltage is 6V, Max current 1.5A, No load current 300mA

Kindly let us know the work around for the same.

over 6 years ago

0 Rick Duncan over 6 years ago

TI__Guru** 114905 points

Hi Velmurugan,

What is voltage is the VCC pin connected to?
What amount of bulk capacitance do you have on VCC and VM supplies?
Can you provide a schematic of the DRV8837 section?

0 Velmurugan Ekambanathan over 6 years ago in reply to Rick Duncan

Prodigy 140 points

Hi Rick Duncan,

I have attached the schematics of the motor section

0 Rick Duncan over 6 years ago in reply to Velmurugan Ekambanathan

TI__Guru** 114905 points

Hi Velmurugan,

Thank you for the schematic. There is nothing obvious from the schematic.

What type of overvoltage protection did you implement at the VM pin?

Have you examined the voltages of VM, OUT1 and OUT2 during operation looking for voltage spikes that could either approach or violate the absolute maximum ratings?

Motor drivers

Motor drivers forum

DRV8837: VM and Vcc gets internal short