LM22676: LM22676 voltage drop

Shmuel Iliaich

Part Number: LM22676

Hi,

I have a design that implemented on a board.

I use the LM22676 to convert 28V to 12V.

The board works but at the last year I have problem in some boards.

when I put a load of 1A the voltage drop down to 8.5V.

My question is what can cause that

Thanks

Shmuel

0 Daniel Li14 over 4 years ago

HI Shmuel:
Can you help show us the schematic of LM22676? and when you see the voltage drop, what Vin condition it is?

And can you help get the waveform of SW, inductor current and Vin, VO so that we can help identify the root cause.

Thanks

Daniel LI

0 Daniel Li14 over 4 years ago in reply to Daniel Li14

Hi Shmuel:

I not see your feedback about this issue, I will close this question, if you have update, you can reopen it.

Thanks

0 Shmuel Iliaich over 4 years ago in reply to Daniel Li14

Hi,

Here is the schematic:

The EN controlled from uC.

At my ATP I'm turnig on the IC and I can see solid 12V.

When I put it under load the voltage drop to 8.5V.

I don't have the current measurments that you asked.

I need to clearfy that this happen 10% of the new boards.

thanks

Shmuel

0 Daniel Li14 over 4 years ago in reply to Shmuel Iliaich

HI Shumel:

I still can't see you attached schematic. Can you resend your schmatic or you can send to my mailbox : daniel-li@ti.com

Thanks

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