TPSM63606: My design is not operating when I turn on power

Alex Wong

Prodigy 170 points

Part Number: TPSM63606

Hi TI Expert,

I am using TPSM63606 in design, step down my Vin (12/24V) to 5V,6A for other buck converter on board.

So I just copying the application circuit datasheet p.22 and layout on p.32,

but when I turn on power (12V), I see EN pin voltage up to 1.67V, but I see no output on VCC / Vout

Is there something i missed in my circuit?

Thanks and Best Regards,

Alex.

Attaching Sch and probed output waveform

3 months ago

+1 Marshall_Beck 3 months ago

TI__Mastermind 30430 points

Hi Alex,

Sorry to hear about your issue.

Thank you for providing all the details.

The schematic appears to be correctly done.

Your comment regarding VCC is disturbing.

VCC should turn on at VIN~3.6V.

Do you see VCC voltage ever in regulation above 3.6V?

If not, then, I think you have either an assembly issue or a damaged part.

+1 Timothy Hegarty 3 months ago in reply to Marshall_Beck

TI__Guru 54422 points

No need for a cap on VCC - it's already integrated in the module. Check if that 100nF external cap on VCC is shorted/cracked, as that will prevent powerup. Also ensure that the test points shown for RBOOT/CBOOT, FB, etc. are not shorted to something.

Tim

0 Alex Wong 3 months ago in reply to Timothy Hegarty

Prodigy 170 points

Hi TI Experts,

Thanks for your advise. I double checked my board by X-ray and found assembly issue Orz
all pins had shifted by 1 pin.

Luckily the IC is still functioning and giving 5V now

Thanks.

Alex.

0 Marshall_Beck 3 months ago in reply to Alex Wong

TI__Mastermind 30430 points

Hi Alex that is good to hear.

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TPSM63606: My design is not operating when I turn on power