UCPD Dead Battery pins are they just internal resisters

[Brenden_PLUS]

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.  

[waclawek.jan]

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]

Hi @Brenden_PLUS 

Did you check the KB article about dead battery?

[Brenden_PLUS]

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.  

 

 

[Carl_G]

How will you switch from a SNK to a SRC if you have permanently affixed Rd?