DC/DC Buck Converter that can sink Current

You might try looking at TPS54320 or TPS54350.

The TPS54550 may work too

Hi All,

Thanks for the tips on using the TPS54320. It seems like a good fit for the job.

I am now trying to just check what the minimum drop out voltage is for the TPS54320. As I would like to put 13V in, and be able to regulate to near 12V. I am unsure whether the boot pin will take care of this, or whether I need to make VIN @ 15V and PVIN @ 13V to be able to drive the high side FET (allowing for a 2V Vgs).

Does the BOOT pin charge across BOOT/PH only?

Or does it act like a charge pump being placed across PH/GND to charge to PH, and then being placed across BOOT/PH to effectively deliver PH+BOOT to the highside FET, thus allowing a very low drop out (but forcing a minimum output voltage).

Dear John,

When these ICs sink current from the output, do they feed the power back into the power source?
For instance, if it is configured to convert 5.0V to 1.8V and it needs to sink 500mA from 1.8V, would it give back ~180mA average to the 5.0V source or does it dissipate the power as heat?

Thanks and Regards,
Subhash