LM5022: 4A through a 2A circuit

Bhanu Indu Sekhar Muppalla

Part Number: LM5022

Hello Team,

This is a circuit we have designed in TI webench. It steps up 48V to 54.6V and 2A. Suppose we draw around 4A from the converter will the converter spark and fail, especially the inductor, capacitor and IC

IF failure happens, What might be the reason for this failure.

Boost1 and Boost2.pdf

Thanks

over 1 year ago

0 Stefan Schauer over 1 year ago

TI__Mastermind 47871 points

Hi Bhanu,

thank you for using the E2E forum.

When loading this power supply with 4 A output load it will reach the current limit of the peak current sense (measured with the current sense resistor).

If this happens current switching cycle will be terminated, so the power supply will not be able to deliver the current with the required voltage.

See also datasheet: 7.3.4 Current Sensing and Current Limiting

Best regards,

Stefan

0 Bhanu Indu Sekhar Muppalla over 1 year ago in reply to Stefan Schauer

Intellectual 400 points

Hello Stefan,

So we had used the above circuit to charge a battery. The charge current was 4.5A. We got a slight burning smell and then before we could figure out from where it was coming a spark came from the side where the inductor was located and the circuit stopped working. So we wanted to know what might have gone wrong and where exactly so that we could replace it

Thanks

0 Stefan Schauer over 1 year ago in reply to Bhanu Indu Sekhar Muppalla

TI__Mastermind 47871 points

Hi Bhanu,

first item to check here would be the inductor (have you used the one in the list: SRR1210-220M) it has a saturation current of 4.5A whereas with 4 A you get a peak of 4.9A. At this point the inductor will saturate and loose its inductance. So it behaves like a piece of wire.

Best regards,

Stefan

0 Bhanu Indu Sekhar Muppalla over 1 year ago in reply to Stefan Schauer

Intellectual 400 points

Hello Stefan,

I will replace the inductor and test the circuit.

0 Bhanu Indu Sekhar Muppalla over 1 year ago in reply to Bhanu Indu Sekhar Muppalla

Intellectual 400 points

Hello Stefan,

How to test if the LM5022 IC is not damaged or burnt out?

Thanks

0 Stefan Schauer over 1 year ago in reply to Bhanu Indu Sekhar Muppalla

TI__Mastermind 47871 points

Hi Bhanu,

this can be only done on a functional basis, e.g. observing the Gate signal to see if this is working as expected.

Best regards,

Stefan

0 Stefan Schauer over 1 year ago in reply to Stefan Schauer

TI__Mastermind 47871 points

Hi Bhanu,

I have not seen an update for the last 12days, so I assume the questions are/or answered and the issue is solved.
I close this thread now. If there is still something open reply and the thread will get open again.
If you have any other question or of the thread gets locked, please open a new one.

Clicking the Resolved Button also helps us to maintain this forum.

Best regards,
Stefan

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LM5022: 4A through a 2A circuit