DRV8303 GVDD doesn't start

masahiko shimizu

Other Parts Discussed in Thread: DRV8303

Hi

My customer is using DRV8303.
He has a issue about charge pump.
After PVDD supply is down, GVDD doesn't start even if PVDD is supplied again and EN_GATE is turned on.
The PVDD supply down is test for customer's product.
In case slow fall time, this event doesn't occur.
Doesn't GVDD start because of the speed of fall time of PVDD?

Best regards
Shimizu

GVDD doesn't start.xlsx

over 8 years ago

0 Rick Duncan over 8 years ago

TI__Guru** 114905 points

Hi Shimizu-san,Our expert has been notified and should reply soon.

0 Nicholas Oborny over 8 years ago

TI__Mastermind 21305 points

Hi Shimizu,

Can you provide a scope capture of the power supply (PVDD1) and GVDD during the power sequence for when the issue happens and when it does not?

0 masahiko shimizu over 8 years ago in reply to Nicholas Oborny

Guru 11235 points

Hi Nick

I requested waveform to customer.
I will send waveform after getting waveform.

And I add information about PVDD supply down(fall).

When the issue happen: 17 V/ms PVDD 24V -> 5V

Not issue happen: 5.7 V/ms PVDD 22v -> 5V

Thanks
Shimizu

0 masahiko shimizu over 8 years ago in reply to masahiko shimizu

Guru 11235 points

Hi Nick

My customer said that "Excel is waveform ".
I attached Excel at first post.
Data of Excel was acquired by an oscilloscope.
A csv file was output from oscilloscope and it was graphed.
Is it useless by Excel waveform?
What are you worrying about in waveform?

Is it possible to check it by the condition that a issue happens?

Thanks
Shimizu

0 masahiko shimizu over 8 years ago in reply to masahiko shimizu

Guru 11235 points

Hi Nick

Thank you for your support.
How is the progress?
I think it's strange that GVDD doesn't return even if user reset with EN_GATE.

Thanks
Shimizu

0 Nicholas Oborny over 8 years ago in reply to masahiko shimizu

TI__Mastermind 21305 points

Sorry Shimizu. I did not see the original waveforms in the excel sheet.

Why does EN_GATE go low during the UVLO event? Does the device report any other faults during the UVLO event other than PVDD_UV?

Can you ask the customer to try and experiment with EN_GATE always high and report the waveforms?

0 masahiko shimizu over 8 years ago in reply to Nicholas Oborny

Guru 11235 points

Hi Nick

　Thank you for your support.

I have requests.

A customer is the very serious situation now.　

Could you tell me the reason that GVDD doesn't return even if a charge pump is reset in EN_GATE?

The condition is that PVDD falls in PVDD 24V -> 5V by 17 V/ms.
Is it possible to check it by the condition that a issue happens?

Is operation of EN_GATE necessary to analyze this issue?
　
Best regards
Shimizu

0 masahiko shimizu over 8 years ago in reply to masahiko shimizu

Guru 11235 points

Hi Nick

I add information about the following.
>The condition is that PVDD falls in PVDD 24V -> 5V by 17 V/ms.

When PVDD fall in 0V, GVDD returns.

Thanks
Shimizu

0 Nicholas Oborny over 8 years ago in reply to masahiko shimizu

TI__Mastermind 21305 points

Hi Shimizu,

Let's take this conversation offline. I sent you a message with my contact information.

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DRV8303 GVDD doesn't start