DRV8824: Motor Driver derating

Daniel Liao

Prodigy 20 points

Part Number: DRV8824
Other Parts Discussed in Thread: DRV8424, DRV8711

What's DRV8824 internally limited spec.？

The datasheet shows 1.6-A Maximum Drive Current at 24 V and TA = 25°C.

If we use the VM is 12V, does it mean we can drive it reach 3.2A?

over 1 year ago

0 Pablo Armet over 1 year ago

TI__Mastermind 37683 points

Hello Daniel,

Someone from our team will be reaching out to you shortly to answer your questions.

Regards,

Pablo Armet

0 Jaya Hari over 1 year ago

TI__Prodigy 251 points

Hello Daniel,

In order to get a better understanding of your situation, I have some quick questions to ask:

Is your original question paired with the assumption that the same amount of power dissipation can be kept by decreasing the voltage from 24V to 12V and increasing the maximum drive current from 1.6A to 3.2A?

Or is the situation that you would like to have a lower thermal dissipation for a higher current (3.2A compared to the 1.6A in the datasheet for DRV8824)?

Regards,

Jaya Hari

+1 Brian Dang over 1 year ago

Genius 5040 points

Daniel Liao said:
The datasheet shows 1.6-A Maximum Drive Current at 24 V and TA = 25°C.

If we use the VM is 12V, does it mean we can drive it reach 3.2A?

Hi,

The 1.6A max output limit is due to the thermal limitation of the internal H-bridge FET, P=i^2 * R, where R is the FET on resistance, and not due to P=V * I. So even of VM is 12v the same 1.6A max is applied.

Brian

0 Daniel Liao over 1 year ago in reply to Brian Dang

Prodigy 20 points

Thanks for your reply.

0 Daniel Liao over 1 year ago in reply to Pablo Armet

Prodigy 20 points

Thanks for your reply.

0 Daniel Liao over 1 year ago in reply to Jaya Hari

Prodigy 20 points

Thanks for your reply. I want to increase the maximum drive current from 1.6A to 3.2A on VM 12V situation.

So, I want to confirm the Peak motor drive output current spec, but I found missed OCP function.

0 Brian Dang over 1 year ago in reply to Daniel Liao

Genius 5040 points

Daniel Liao said:
Thanks for your reply. I want to increase the maximum drive current from 1.6A to 3.2A on VM 12V situation.

1.6A is continuous output current, and it will trigger the OCP if the current is 1.8A or higher; therefore, 3.2A is a wishful unrealistic dream.

Brian

0 Ryan Kehr over 1 year ago in reply to Brian Dang

TI__Guru 55565 points

Daniel,

Our highest power stepper motor driver is the DRV8424 which has a min OCP of 4A. This would technically meet your specification.

Full scale current is still thermally limited to 2.5A. If you need full scale current of 3.2A, you will need to consider a gate driver like the DRV8711 with external FETs.

Regards,

Ryan

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DRV8824: Motor Driver derating