DRV8301 The OC detection timing chart

masahiko shimizu

Other Parts Discussed in Thread: DRV8301

My customer is using DRV8301 .
Could you let me know the OC detection timing chart?
I want to know the following as detail.

- When does OC detection start?
->Is INH_x/INL_x when it was high? Is there delay time?

- When does OC detection end?
->Is INH_x/INL_x when it was low? Is there delay time?

Thanks,
Shimizu

over 9 years ago

0 Wilson Zuo over 9 years ago

TI__Mastermind 26065 points

Hi Shimizu

OC detection is performed on detecting the Vds when the referred MOSFET is turned on. So the start detecting time is the Toc(1.5us) after INH_x or INL_x is high. When INH_x/INL_x is low, the corresponding OC detection will end immediately.

Best regards,

0 masahiko shimizu over 9 years ago in reply to Wilson Zuo

Guru 11235 points

Hi Wilson

Thank you for your support.
I have a additional question.

In case of OCP, How long is time from OC detection to alerting fault-pin?

Thanks
Shimizu

0 Wilson Zuo over 9 years ago in reply to masahiko shimizu

TI__Mastermind 26065 points

Hi Simizu

It is only logic propagation delay from OC detection to nFAULT asserting. Should be <1.5us. If you need accurate data, we will check with design side but may need to wait for longer time since now the Holiday season.

Best regards,

0 masahiko shimizu over 9 years ago in reply to Wilson Zuo

Guru 11235 points

Hi Wilson

Thank you for your support.

I would like to know accurate data. Could you let me know the confirming result?

My customer need this information to advance their development .

Thanks

Shimizu

0 masahiko shimizu over 9 years ago in reply to masahiko shimizu

Guru 11235 points

Hi Wilson

I inform detail request.
I would like to know the following.
My customer has some issue about OC event on debugging their board.

- When does OC detection start? I want to know delay time until entering detection mode.
- I want to know logic propagation delay from OC detection to nFAULT asserting.

Thanks
Shimizu

0 masahiko shimizu over 9 years ago in reply to masahiko shimizu

Guru 11235 points

Hi Wilson

Could you tell me about the progress on this?

Thanks
Shimizu

0 masahiko shimizu over 9 years ago in reply to masahiko shimizu

Guru 11235 points

Hi Wilson

I got the attached file information.
Please see page 3 Figure1.
Is this circuit of OCP same with DRV8301?

If it is same circuit, I think that "OC sensing response time" is time from detection OC to the fault flag output.
If it is not same circuit, Please let me know the detail of OCP detection.

Thanks,
Shimizuslva505.pdf

0 Wilson Zuo over 9 years ago in reply to masahiko shimizu

TI__Mastermind 26065 points

Hi Shimizu

The structure of OC detect is simular as in this file.

The OC detection and response of the DRV8301 is related to the OC_MODE.

In OC latch mode, the OC detection will start to look at the Vds voltage after 1.5us Toc time, then, if OC event detected, the nFAUTL will assert 200ns after the event detected.

Thanks,

0 masahiko shimizu over 9 years ago in reply to Wilson Zuo

Guru 11235 points

Hi Wilson

Thank you for your support.
I would like to confirm just in case;
What is a trigger of 1.5us? High input of INH_x/INL_x? or High output of Pre-driver?

Thanks
Shimizu

0 Wilson Zuo over 9 years ago in reply to masahiko shimizu

TI__Mastermind 26065 points

Hi Shimizu

This 1.5us should refer to an internal logic signal when turing on the pre-driver. Since there is just <50ns delay from input to INH_x/INL_x changing. We can ignore this reference difference to the OC time. Normally we can use the inputs for the time reference.

Best regards.

0 masahiko shimizu over 9 years ago in reply to Wilson Zuo

Guru 11235 points

Hi Wilson

Thank you for your support.
I understood.
This answer is easy to understand.

Thanks
Shimizu

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DRV8301 The OC detection timing chart