DRV8307 Charge pump failure

masahiko shimizu

Other Parts Discussed in Thread: DRV8307

My costomer is using DRV8307.
Could you let me know charge pump failure(CPFAIL)?

　- Does CPFAIL function become to the enable state at time of becoming low level of ENABLEn pin?
- Does Charge pump become to the enable state at time of becoming low level of ENABLEn pin?
　- When ENABLEn was made Low in the state in which PWM doesn't input.
Does fault occur because monitoring starting of CPFAIL is earlier than charge pump starting(VCPFAIL was exceeded)?

Thanks,
Shimizu

over 10 years ago

0 Wilson Zuo over 10 years ago

TI__Mastermind 26065 points

Hi Shimizu

Deasserting of ENABLEn will cause the motor coasts. After motor is stopped (No HALL transitions) for 1s, then DRV8307 will enter a low-power standby state(sleep).
At low-power mode, the charge pump should stopped. The VCP monitoring will alive just when charge pump is alive. Also the monitor is working as a UVLO function, it is an auto recovering function. So I don't think it will cause any problem even when the monitor start alive slightly earlier or later of VCP rising.

Do you know why customer asking about this?

Best regards,

0 RE over 10 years ago

TI__Mastermind 20985 points

Shimizu-san, it is normal for nFAULT to go Low for about 150us when Enable becomes active, and you are correct that it is a result of monitoring the charge pump voltage as it turns on.

Best regards,
RE

0 masahiko shimizu over 10 years ago in reply to RE

Guru 11235 points

Hi RE and Wilson

Thank you for your support.
Your answer is correct. My customer has issue.
This issue is that Fault occur for 150us when enable becomes active.

Thanks
Shimizu

0 RE over 10 years ago in reply to masahiko shimizu

TI__Mastermind 20985 points

If your controller is monitoring fault, hopefully you can have it ignore the signal for the first 1ms.

Best regards,
RE

0 masahiko shimizu over 10 years ago in reply to RE

Guru 11235 points

Hi RE

Thank you for your support.

I understood.

Thanks

Shimizu

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DRV8307 Charge pump failure