TPS62172: Vout does not reach the desired value of 3.3VDC

G Layaz

Part Number: TPS62172
Other Parts Discussed in Thread: TPS62171

Hi,

I would like to use the TPS62172 for my embedded system. I could use 3 or 4 standard batteries, 4.5VDC or 6VDC, for the Vin of the TPS62172 and I would like 3.3VDC for Vout.

I attachment, you can see waves of my system... it doesn't work and Vout stays at 1.8VDC.

For the PCB, I followed advices from the slvu483 document, the only difference, I use a 4 layers PCB.

Thanks for your advicesTPS62172.pdf SCH-PCB.pdf.

over 6 years ago

0 Ivo over 6 years ago

TI__Intellectual 880 points

Hello,

schematic and power up plot look fine.
I think you use the 1.8V output voltage version of the device - TPS62171.
TPS6217x is available in 1.8V - 3.3V - 5V device voltage options.

Best regards,
Ivo

0 Chris Glaser over 6 years ago

TI__Guru*** 142750 points

Hi G,

Thanks for posting your schematic and layout. Are those ceramic caps for C60 and C61? If so, these look fine at first glance.

Can you read the markings on the top of the IC? There is a 1.8Vout version as well.

Finally, can you measure Vout with a normal multimeter to confirm the 1.8V reading?

0 G Layaz over 6 years ago in reply to Ivo

Prodigy 210 points

Hello Ivo,

What a shame... you are right :-(

Thanks!

0 G Layaz over 6 years ago in reply to Chris Glaser

Prodigy 210 points

Hi Chris,

the marking is QUFO 65K CNLF.

Greg

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TPS62172: Vout does not reach the desired value of 3.3VDC