TPS51220: 12V Output Using TPS51220EVM

Adam Mc Gaffin

Part Number: TPS51220

Team,

I am trying to validate the TPS51220 which I plan to add to my EVM. I need the device to output 12V and 5V. I cannot get the EVM to output 12V on either channel. For VOUT2, I changed the R21 to a value of 297k ohm, and left R24 at 27k ohm. After populating this resistor, VOUT2 does not output anything, and if I try to repopulate R21 to the original value, it is unable to output 3.3V. I then tried to reprogram VOUT1 to output 12V by changing R2 to 330k ohm, and depopulating R22, but the EVM is still unable to output 12V. Any help would be appreciated.

over 4 years ago

0 Yuchang Zhang over 4 years ago

TI__Mastermind 18510 points

Hi, if the Vin is proper, I suppose the Vout already short to Ground, because the Vout is over the output cap rating spec too much. If yes, you can Change the output cap to try.

Yuchang

0 Yuchang Zhang over 4 years ago in reply to Yuchang Zhang

TI__Mastermind 18510 points

Also by the way, if you use VO1 output 12V, you must disconnect the output of VO1 to V5SW, If not, the V5SW may be damaged by 12Voutput.

0 Adam Mc Gaffin over 4 years ago in reply to Yuchang Zhang

TI__Mastermind 28760 points

Hi Yuchang,

The capacitor voltage rating was the issue. Once I de-populated the old capacitors, and populated ones that could handle greater than 12V, was able to successfully output 12V on VOUT2

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TPS51220: 12V Output Using TPS51220EVM