DRV8308EVM: DRV8308

QIURUI LI

Prodigy 10 points

Part Number: DRV8308EVM
Other Parts Discussed in Thread: DRV8308

Debug problems of DRV8308.pdf

over 3 years ago

0 Matt Hein over 3 years ago

TI__Mastermind 21805 points

Hello Qiurui,

Is this the same request as https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1012180/drv8308-motor-debugging?

Thanks,

Matt

0 Matt Hein over 3 years ago in reply to Matt Hein

TI__Mastermind 21805 points

Hello Qiurui,

The DRV8308 requires the speed loop to be tuned to the motor, and we do not expect that the DRV8308 settings will work across different motors.

I need to review your settings to see if I can offer any suggestions.

Have you tried bypassing the comparator to see if performance improves on the second motor?

Thanks,

Matt

0 QIURUI LI over 3 years ago

Prodigy 10 points

Matt,they are the same question.I have tried bypassing the comparator,However, the performance has not improved on the second motor.I also found a phenomenon that when the speed deviation is very large (estimated to be more than 30%), the lockn indicator of EVM board begin changes color, and it's the same when the speedth setting is 0.78% or 6.25%.

+1 Matt Hein over 3 years ago in reply to QIURUI LI

TI__Mastermind 21805 points

Hello Qiurui,

They may need to increase the SPEEDTH in order to have a wider tolerance for LOCK. If the DRV8308 drops out of LOCK then the commutation switches from SINE to TRAP.

Please take note that July 5 is the Independence Day holiday in the US. The team is out of office and will get back to you as soon as they return!

Thanks,

Matt

0 QIURUI LI over 3 years ago in reply to Matt Hein

Prodigy 10 points

Hi,Matt.If I use closed-loop control, does the three pins :FGGB / FGINN / FGINP need external signal? If necessary, what signal should be connected to them? It can't be Hall signal, because the hall signals had been connected to drv8308. At present, the three pins are not connected. Does the closed-loop control problem have anything to do with it?

0 Matt Hein over 3 years ago in reply to QIURUI LI

TI__Mastermind 21805 points

Hello Qiurui,

Those pins are to be used with an FG trace. If you do not have an FG trace, please leave these pins unused. You can look at www.ti.com/.../TIDA-00197 to see how it is done in that design.

See this image for an example of an FG trace on a motor:

Thanks,

Matt

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DRV8308EVM: DRV8308