I'm a LDO moron! 820-01041

[KC Micro Tronix]

Board does not switch to 20v
Checked all 4 CD3215's

(2) PP1V8 LDOD works regardless of port
(35) PP1V1 LDO works but is chip specific
(53) PP3V3 LDO works regardless of port
(75) PP1V8 LDOA works regardless of port

How do these all communicate?
Do they talk to a outside system like a PCH?
Which LDO is usually a smoking gun for identifying a bad CD3215?
Is there good literature on this system and how it works I can read?

 

[piernov]

CD3215 Bootup Sequence - LogiWiki

We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area

logi.wiki

T2 and CD3217 Power on Sequence - LogiWiki

We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area

logi.wiki

It's of course still missing a lot of info but feel free to contribute with your findings.

 

[KC Micro Tronix]

awesome ty

 

[2informaticos]

1V1 LDO (LDO_BMC) can help, being chip specific.

Other LDO rails are shared between CD3215 pair chips.
Can still help to discard 2 from 4 chips.

Good information regarding power on sequence on above mentioned website.

TI doesn't help with datasheet, but power delivery protocol is not chip dependant, so we can get some information from other manufacturers, like Richtek.

Introduction to Richtek USB Type-C Power Delivery Solutions | Richtek Technology

www.richtek.com

SMC talks with CD3215 through I2C bus and CD3215 talks with charger through one of CC1/2 lines, according with connection sense.