TPS2120: How to switch to IN2 only when there is no IN1 voltage

Baek JongHak

Prodigy 70 points

Part Number: TPS2120
Other Parts Discussed in Thread: TPS2121,

Hi,

IN1 : Main Battery (3 ~ 4.2v)

IN2 : Sub Battery (3 ~ 4.2v)

The sub_battery(IN2) is intended to be used for a while when the main battery(IN1) is removed or fully discharged.

PR1, OV1, OV2 and SEL are all connected to Gnd.

Currently, chattering occurs in either IN1 or IN2.
I think it's because of the comparator.

Is there a way to disable the comparison?

Thanks

Mark.Baek

over 4 years ago

0 Timothy Logan over 4 years ago

TI__Mastermind 19044 points

Mark,

Could you share a schematic on how your TPS2120 is connected? From what you describe it seems like your design would do well with the TPS2121 for the "automatic switchover" mode described in the datasheet (see http://www.ti.com/lit/ug/tidue50/tidue50.pdf):

This will let you configure a hysteresis level so that you won't have chattering when you switch between IN1 and IN2.

0 Baek JongHak over 4 years ago in reply to Timothy Logan

Prodigy 70 points

For the moment, it seems that PR1 connects to IN1 and works as desired.
We will test it further and contact again if the problem persists.

Thank you very much.

Power management

Power management forum

TPS2120: How to switch to IN2 only when there is no IN1 voltage