LMR23625: Current limit

GARETH OU

Part Number: LMR23625

Please confirm whether LMR23625 CURRENT LIMIT is normal? It is calculated to be about 3.91A, and the load is 5A as shown in Figure 5A (the voltage drops a little, RIPPLE becomes larger), it must be pulled to about 20A before the output voltage will drop, as shown in Figure 22A

over 4 years ago

0 Andy Chen over 4 years ago

TI__Mastermind 34875 points

Hi Gareth,

Can you measure the inductor current waveform? this will check the current limit more accurately.

B R

Andy

0 GARETH OU over 3 years ago in reply to Andy Chen

Guru 11435 points

Hi Andy

The test is as shown in the picture. Although the maximum value of INDUCTOR CURRENT is 4.85A, the output has been pulled to the upper limit set by the load, 20A. And why the voltage has not reached 0V,

0 Denislav Petkov over 3 years ago in reply to GARETH OU

TI__Mastermind 19891 points

Hello Gareth,

The inductor current (channel 3) shows that the part hits current limit as expected and enters hiccup mode. After two cycles of hiccup mode the overload goes away and the output ramps back up. VOUT seems to pull up quickly and almost looks like it is prebiased by some other rail.

Can you please share your schematic and indicate where you are measuring the load current?

Thanks,

Denislav

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LMR23625: Current limit