Power management

Power management forum

LM5118-Q1: LM5118-Q1

manmohan singh

Prodigy 10 points

Part Number: LM5118-Q1

Hi Team,

I have design 9-36Vin to 24Vout @3A power supply using Lm5118-Q1 IC, I have used the components value recommended by Webench design for the same. Everything is working fine. but during short circuit test I am still getting output of 1Vout @10A and diodes are getting heated. The controller is not turing off the mosfets during short circuit condition.

over 2 years ago

0 manmohan singh over 2 years ago

Prodigy 10 points

file:///D:/Downloads/WBDesign18_Input%20Transient-3%20(1).pdf

0 Feng Ji over 2 years ago in reply to manmohan singh

TI__Genius 17085 points

Hi Manmohan,

manmohan singh said:
file:///D:/Downloads/WBDesign18_Input%20Transient-3%20(1).pdf

I can not access the schematic as this is text.

Best Regards,

Feng Ji

0 manmohan singh over 2 years ago in reply to Feng Ji

Prodigy 10 points

Schematics Hi please check this.

0 manmohan singh over 2 years ago in reply to manmohan singh

Prodigy 10 points

Hi any leads?

0 Feng Ji over 2 years ago in reply to manmohan singh

TI__Genius 17085 points

Hi Manmohan,

Cycle by cycle current limit is triggered at short circuit condtion, so you can see 10A at short circuit.

Add C21 as shown below to enter hiccup mode, which may help to improve the heat.

Best Regards,

Feng Ji

0 manmohan singh over 2 years ago in reply to Feng Ji

Prodigy 10 points

Thank you, Feng.

I have Implemented Your comment, still the diodes heat in similar way. So, can we conclude this as fundamental behavior of the IC.

will there be any probability of component failure if I kept it for a long time in short circuit condition.

0 Feng Ji over 2 years ago in reply to manmohan singh

TI__Genius 17085 points

Hi Manmohan,

You may increase C21 to extend the hiccup off time for better thermal. You may also try to reduce the peak current limit.

Component may fail if it is over temperature.

Best Regards,

Feng Ji

0 manmohan singh over 2 years ago in reply to Feng Ji

Prodigy 10 points

Thank you, Feng.

I will implement your comment.