TPS54541: Regulator not able to load beyond 500mA

Vishal Kakade1

Expert 1590 points

Part Number: TPS54541

Hi Experts.

I have designed a buck converter with the below specifications.

Vin: 18V to 36V (Vin Nominal is 24V)

Vo: 12V at 5A.

I am using the same circuit as recommended by Webench. The only difference is, I have connected the PGOOD to MCU's input pin which is pulled to 3.3V. Whenever I am driving the current, the voltage is dropping to ~4 to 6V.

What Can go wrong here?

Regards

Vishal

over 3 years ago

0 Rahul Raj over 3 years ago

Prodigy 30 points

I would like to attach a simulation file , to add to the above. Simulation results show that the device can be loaded with 5A at 12V with same design. I have not used the same diode as in design . But we are unable observe the same in the card.

Regards ,

Rahul

TPS54541_30jun2021.TSC

0 Arief Hernadi over 3 years ago in reply to Rahul Raj

TI__Mastermind 23815 points

Hi,

Do you have the waveform of Switch node when the load is applied?

Also do you have the layout for the design?

Thanks

-Arief

+1 Vishal Kakade1 over 3 years ago in reply to Arief Hernadi

Expert 1590 points

Hi Arief,

We resolved the issue. The issue was with the Schottky diode. We were using a diode with more forward drop. After replacing the diode with a smaller VfB, it's working fine.

Regards

Vishal

Power management

Power management forum

TPS54541: Regulator not able to load beyond 500mA