TPS61200 - R1 and C2 on EVM

Hi Daisuke,
R1 and C2 forms a RC filter for the input of the IC. It can help filter some noise if Vin is not clean so that IC could see a cleaner power supply.

BR
Gene

Hi Gene Lu,

I was looking for this answer. Thank you.

Nevertheless, I'm surprised that R1 value is about 100oHms. I think it will dramatically decrease the voltage on Vin when the load will increase. I know it should not be a problem because it has been developped and tested ;).

Could you, please, explain why it is not a problem ?

If I want to use the ULVO feature, R16 should be connected to C1 - R1 net. Is that correct ?

Regards (and happy new year)

Hi Steven,
There's no large current going through R1, since the main power will go through L1 and into SW (pin3). So there's no worry about large voltage on R1.
If you want to use the UVLO function, just refer to the user's guide and adjust R2 and R3.

BR,
Gene

Hi Gene,

Thank you for your answer.

By the way, do you know more precisely, how much current going through R1 ?

For the UVLO function, I wanted to writte R2 no R16 :). Sorry.I have my answer now :)

Have a nice day.

Hi Steven,

The current going through R1 is around 2uA, which is the Iq. It may be a little different with different Vin and temperatures.

BR,

Gene