LM5023: Protection ajustment LM5023

Bruno Pescarolli

Part Number: LM5023

Tool/software:

Hi!

I have a SMPS project ... , I was reading the datasheet and I had doubts about the calculations of R1, R2, R_external and R_sense.

I need to determine over current and over voltage protection ... from what I can understand... R1, Rsense, Rexternal are related to starting current, while R2 is related to overvoltage? Is this correct?

I'm using it on R2 2k2, R1 23k7... on Rsense 0.43R and on Rexternal 374R ...

My output is 6.3V, and I'm noticing that for every 100mA I increase my load (up to 1.3A), I need to increase my input by 10VAC... for example:

Input 64VAC, load 400mA, when starting, the output pulsates, indicating protection. It starts after increasing my 10VAC (74VAC) input ...

1 month ago

0 Dushyanth R 1 month ago

TI__Prodigy 440 points

Hi Bruno,

I will get back to you on this.

Regards

Dushyanth

0 Dushyanth R 1 month ago in reply to Dushyanth R

TI__Prodigy 440 points

Hi Bruno,

Yes. sleect R1 , Rsense and Rexternal based on the overcurrent spec and ten select R2 on OVP

Regards

Dushyanth SR

0 Bruno Pescarolli 1 month ago in reply to Dushyanth R

Prodigy 30 points

Hi Dushyanth R , firstly of all ... thanks for the feedback ...

The formulas are those found in the datasheet, what is the maximum starting current that I can adjust?, another thing... is it recommended to start without adjusting the current (without R1)?