TPS61235P: TPS61235P

Ray Breslau

Part Number: TPS61235P

I have built a small circuit board with a TPS61235. The schematic I use was identical to that shown on the spec sheet for the TPS61235. I laid out the printed circuit card exactly as shown on the spec sheet. However, when I apply 3.5vdc to the input and enable I don't get any output voltage with no load or even a small load. What am I missing!

over 3 years ago

0 EM over 3 years ago

TI__Genius 11215 points

Hello,

Thanks for reaching out. Do you mean that you copied the circuit at pg1 of the datasheet? Did you add the recommended pull down resistor on the EN pin?

Kind regards

0 Ray Breslau over 3 years ago in reply to EM

Prodigy 10 points

Yes. I have a 1 Meg resistor from EN to ground

0 Eric Yue over 3 years ago in reply to Ray Breslau

TI__Expert 5180 points

Hi Ray,

Did you connect FB to VOUT pin for fixed output voltage? You can compare the design between 61236EVM and your board except for FB pin connected to Vout and make sure EN, CC, and INACT connection is correct. The layout of GND and input/output capacitors require special attention.

Can you share the schematic and layout? and can you measure SW, Vout waveforms and test EN, CC, and INACT voltage?

Best Regards,

Eric Yue

Power management

Power management forum

TPS61235P: TPS61235P