DRV8850: Consideration of using VM=2V

na na78

Guru 16770 points

Part Number: DRV8850

For brushed DC motor opeartion, use of VM=2V is required.

Motor specification is following.

VM=2V

Istart=2A

Ilock=4A

In addition, motor lock detection function should be implemented in system.

DRV8850 has VPROPI, so current sense output can feed-back to MCU (ADC) and MCU can shut off the driver with specific current.

However, there is concern of using DRV8850 with VM= 2v because of UVLO.

Do you give us advice to use DRV8850 with VM=2V?

Or can you provide other solution for this requirement?

BestRegards

over 6 years ago

0 Mostafa Shubbar over 6 years ago

TI__Prodigy 190 points

Hello,

The minimum operating supply voltage is 2V in order for the device to work properly. VCC UVLO will occur and H-Bridge outputs will shut down between 1.95V and 2.0V. Is it possible for you to consider a boost converter to increase VM?

0 na na78 over 6 years ago in reply to Mostafa Shubbar

Guru 16770 points

Hi Mostafa

We will change VM higher if possible.

What we have to realize is to keep motor speed.

Is it possible to adjust motor speed by input duty to keep speed as same as when VM=2V?

BestRegards

0 Mostafa Shubbar over 6 years ago in reply to na na78

TI__Prodigy 190 points

Hello,

Yes, it is possible to change the speed by changing the output duty using the MCU. You can get an idea of how to do this by looking at the DRV8850EVM.

Regards,
Mostafa

Motor drivers

Motor drivers forum

DRV8850: Consideration of using VM=2V