LM25069: LM25069-2 Restart Issue

Vincent Li00

Intellectual 2035 points

Part Number: LM25069
Other Parts Discussed in Thread: LM25066

Hi Guys

Our customer is using our LM25069-2 as Hotswap application. 12Vin, 12Vout. They tested the current limit operation:

1. Normal room temperature: CH2: 12Vout. Ignore CH1； We can see the restart time is about 2.62s. It is right. Just short the output 12V to GND for 0.5s.

2. -10C temperature: CH1: 12Vout. Ignore CH2； We can see the restart time is about 2.62s. It is incorrect. Just short the output 12V to GND for 1.5s.

Please find the Sech:

So why is ti different at different operation temperature? Could you help us check if our application circuit is correct?

Your feedback are appreciated.

-Vincent

over 5 years ago

0 Vincent Li00 over 5 years ago

TI__Intellectual 2035 points

Correct the error：
The second waveform: the restart time is about 244ms. so it is incorrect.
Thanks
-Vincent

0 Rakesh over 5 years ago in reply to Vincent Li00

TI__Guru* 95611 points

Hi Vincent,

Can you please send waveform capturing Vout, GATE, Timer voltage and input current.

Best Regards,
Rakesh

0 Rakesh over 5 years ago in reply to Rakesh

TI__Guru* 95611 points

Hi Vincent,

Did you get any update on the test waveform from the customer

Best Regards,
Rakesh

0 Vincent Li00 over 5 years ago in reply to Rakesh

TI__Intellectual 2035 points

Hi Rakesh

I have told them to test what you mentioned before. So far we didn't get any waveform from customer. I will call them and ask for this update. Thanks Rakesh.

Thanks

-Vincent

0 Vincent Li00 over 5 years ago in reply to Vincent Li00

TI__Intellectual 2035 points

Hi Rakesh
We have solve the problem by jumping wire on OUTPUT. We found our OUTPUT trace disturbed. But now we don't see any issue so far after we jumped the wire. We want to request for the calculation about LM25069. Could you send me a calculation tool about the external components around LM25069? If you have no, you can also send the related device similar to LM25069.
Thanks
-Vincent

0 Rakesh over 5 years ago in reply to Vincent Li00

TI__Guru* 95611 points

Hi Vincent,

Nice to hear that and thanks for your efforts.
Unfortunately, we don't have calculation tool for LM25069. You can suggest to use LM25066 design calculator to check the SOA margin but note UVLO, OVLO threshold are different.

Best Regards,
Rakesh

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LM25069: LM25069-2 Restart Issue