UCD90320: enable pins will not de-assert

Hello

sequencing off dependencies does not initial the turn off.

If you want to turn off 3V3 if 12V has UV fault, please do the followings

1. enable the UV fault response of 12V. make sure to not select ignore

2. set the 3V3 rail as the fault shutdown slave of 12V rail.

So when a UV fault is detected on 12V rail, 3V3 rail will be off accordingly.

Please refer the attached quick guide for the settings.

2046.UCD90xxx Quick Guide.pptx

Regards

Yihe

Thanks Yihe,

unfortunately the suggestion did not work

set the fault for UV on 12V and adding 3p3V in "Fault Shutdown Slaves" .  

Fault response set to shutdown with delay ( not sure where to set the delay ).  restart 1 time ( ??? )

Enable signal for 3.3V is still high even though 12V is shutdown.

btw, all the rail states in system monitor show up either "regulation" or seq_on" and not as "ramp"  shouldn't they be in "ramp" state?

Hello

The settings are not right.

#1. Retry shall not be used for the 12V UV fault response. since retry is only applied on the 12V. before retry is completed, 3V3 will stay on.
#2.  The delay is the turn off delay for each individual rail.

#3. Be sure that 3V3 is set as fault shutdown slave of the 12V(this need be done from 12V rail configuration settings).

if you can not make it work, send me the project file. I can help review.

Regards

Yihe

version 0727_wip attached.  btw, with no retries the system does not power up at all.  waiting for the fault to clear. 

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/196/version_5F00_0727_5F00_wip.7z