LM5118: I want to improve efficiency

jesus britoloaiza

Prodigy 60 points

Part Number: LM5118

Hi TI experts...

I have a design with these parameters:

Vin = 11 V - 48 V

Vout = 12 V

Iout = 5 A

f = 100 kHz

This is the circuit

these are my measure data:

I would like to raise my red dots above 70%, what do you recommend me to do?

thank you very much in advance.

over 2 years ago

0 Stefan Schauer over 2 years ago

TI__Guru 53711 points

HI Jesus,

a good way to find out where the losses are coming from is the Webench tool.

https://webench.ti.com/

Here you can setup your design and also replace the suggested components with customized ones.

After that you can set your operation conditions and see which component are generating which losses, so that you can optimize that point and then also check if there are other side effects which can accept or not.

I assume the mayor influence will be done by the Diodes. So you may start with them.

Best regards,

Stefan

0 jesus britoloaiza over 2 years ago in reply to Stefan Schauer

Prodigy 60 points

good afternoon, what is the best way to improve the diodes?

+1 Stefan Schauer over 2 years ago in reply to jesus britoloaiza

TI__Guru 53711 points

Hi Jesus,

check for forward voltage drop and reverse recovery charge.

This two reports can also help to better understand where the losses are coming from and how they depend on each other:

2003 Power Seminar - Under the Hood of Low-Voltage DC/DC Converters (ti.com)

Topic_3_Lynch.pdf (ti.com)

Best regards,

Stefan

+1 jesus britoloaiza over 2 years ago in reply to Stefan Schauer

Prodigy 60 points

My measurements had been incorrect, by making the correct measurements the circuit improved remarkably.

thank you very much.

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LM5118: I want to improve efficiency