switching from battry to usb power component

Hi Or,

You can use one dual channel load switch (active high) and a mosfet on one of the enables with a pull up resistor. The battery connects to input where the mosfet is while the usb voltage connects to the other input and other enable. When there is a USB voltage it'll drive the FET LOW disabling the battery side but turning on the usb side.

This is a very simple design but this is a good start. Below is a link to the current limiting switch portfolio so that you can narrow down an IC based on your requirements.

http://www.ti.com/paramsearch/docs/parametricsearch.tsp?family=analog&familyId=524&uiTemplateId=NODE_STRY_PGE_T

Regards,

Darwin

Darwin Hi

thank you very much for your answer.

I have a question, if I use pull up - on the side of the battery (the battery positive side?) doesn't it means that I empty my battery through this pull up all the time?

maybe, I didnt got it right, can you please add a drawing or application note? 

thank you again.

Hi

why not to use TPS2115A? doesnt id to the same?

the problem that most of the timw I am working on a battery so I need very low power switch, do you have any recommendations?

thanks,

Hi Or,

Yes the TPS2115 would work in your application. Remember there will be voltage on both rails but you want priority of USB. Therefore, you'll need some logic to implement this. You can look at table 1 in the datasheet as a guide.

Regards,

Darwin

Darwin Hi

thanks for your answer.

the problem with it is that this is relatively old component with big power consumption.

do you have something newer? less power consuming?

Regards,