TPS40211: Programmable power supply design

Hello,

In general it depends if you want to create 5V from the 4.5V or if the input voltage is always higher than the output voltage. In this case, a buck solution would be the right solution. If you need 5V from the 4.5V as well, then you need a buck-boost solution, so e.g. a SEPIC converter and then TPS40210/1 or LM5155 could be good starting points. 

But possibly the simplest solution would be LM5176 which is a 4-switch buck-boost controller that is designed for this type of application.

BTW, please always use in addition a resistor divider on the FB pin to be sure that the output is never open.

Here some articles about output voltage changing:

https://e2e.ti.com/blogs_/b/powerhouse/posts/adjusting-vout-in-usb-type-c-and-wireless-charging-applications-part-1

https://e2e.ti.com/blogs_/b/powerhouse/posts/adjusting-vout-in-usb-type-c-and-wireless-charging-applications-part-2

Best regards,
Brigitte

Hi Brigitte,

Thanks for the pointers, that was exactly what i was looking for.

i think TPS40210/1 would be a better option as less components are involved and with LM5176/4 switches switching , don't know what kind of problems would prop up. 

But for TPS40210/1, its mentioned as "TPS4021x4.5-V to 52-V Input CurrentMode BoostController" , so there is no possibility for buck mode,

So my requirement of getting  5V from < 5V would fail right.

Best regards,

Vinayak