DRV8824: How to input STEP signal without excitation of motor

Kuramochi Tadahiko

Guru 28715 points

Part Number: DRV8824

Hi,

My customer is requiring that inputting STEP signal without excitation of motor.

("without excitation of motor" means that H-bridge is disable condition)

Because they would like to set not home position when restarting from sleep.

Is it possible?

Best Regards,

Kuramochi

over 4 years ago

0 Wang5577 over 4 years ago

TI__Guru 56650 points

Tadahiko-san,

Understand. It is possible. The STEP pin will advance the indexer when the device is awake and outputs are disabled. But, we need to confirm this. Do you have an EVM to check it?

0 Kuramochi Tadahiko over 4 years ago in reply to Wang5577

Guru 28715 points

Wang-san,

Thank you for your help.

> It is possible. The STEP pin will advance the indexer when the device is awake and outputs are disabled.

We have the EVM.

Could you tell me how to control?

Best Regards,

Kuramochi

0 Wang5577 over 4 years ago in reply to Kuramochi Tadahiko

TI__Guru 56650 points

Tadahiko-san,

1. Set nSLEEP high

2. Keep nRESET low

3. Add STEP signal.

0 Kuramochi Tadahiko over 4 years ago in reply to Wang5577

Guru 28715 points

Wang-san,

Thank you for your reply.

Did you check above on the EVM?

The data sheet says that "The STEP input is ignored while nRESET is active".

Best Regards,

Kuramochi

0 Wang5577 over 4 years ago in reply to Kuramochi Tadahiko

TI__Guru 56650 points

Tadahiko-san,

The 8.3.6 section's statement and nRESET pin function description are conflict in the datasheet. The nRESET pin function description ( nRESET pin: Active-low reset input initializes the indexer logic and disables the H- bridge outputs. Internal pulldown.) should be true.

I don't have a DRV8824EVM on hand. You can verify it with your EVM.

0 Kuramochi Tadahiko over 4 years ago in reply to Wang5577

Guru 28715 points

Wang-san,

Could you revise the datasheet in the near future?

It is required when we submit delivery specification to my customer.

Best Regards,

Kuramochi

0 Wang5577 over 4 years ago in reply to Kuramochi Tadahiko

TI__Guru 56650 points

Kuramochi,

I have added this issue to our datasheet to do list. The datasheet will be updated when we do the DRV8824 datasheet update next time. But, I can not promise the time frame.

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DRV8824: How to input STEP signal without excitation of motor