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UCPD Dead Battery pins are they just internal resisters

Brenden_PLUS
Associate III

I'm using a stm32G0 with a UCPD and i'm trying to figure out if the Dead battery pin have any other benefit then just saving the need for 2 resisters on the board.

 

From my understanding i could create the same functionality of the dead battery pin by just connecting the CC lines to ground with a 5.1K resister.  

3 REPLIES 3
waclawek.jan
Super User

In the 'G0 these resistors can be disconnected by either grounding the respective UCPDx_DBCC pins (and that works with powered-down mcu, too), or during runtime by the UCPD module's logic, see SYSCFG_CFGR1.UCPDx_STROBE bits and the UCPD chapter in RM.

This may or may not be needed in your particular application.

JW

FBL
ST Employee

Hi @Brenden_PLUS 

Did you check the KB article about dead battery?

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.




Best regards,
FBL

I did read this and i still don't understand really any benefit to having these dead battery pins internal to the chip vs having them external.  Other then you can save 2 resistors on the board.

 

I know you can disable these resister's so you can use the gpio pins for something else.  But if your using the UCPD chip with the dead battery then i don't see why you would want to disable this resistor?  

 

If it is just conclusion is that the only benefit to these dead battery pins is that they safe 2 resistors then thats fine.  I'm just trying to figure out if i'm missing something.  Like this seems like a lot of work to put this inside the chip to save 2 resistors.  From my understanding you could do both 1 and 3 with a external resistor instead of going to the DBCC pins.