Hi,
Please find attached my UDC90120A design
The board is powered from the P3V3_PREFET and PVPWR rails. Some additonal rails are sequenced depending on these 2, others are just monitored by the UCD90120A.
I've got my power-on sequence working
If P3V3_PREFET and PVPWR are both good, step1) enable P1V0, step2) enable P1V8 and P2V0, step3) enable 'others'
I've got my power-off sequencing working
If either PV_PWR or P3V3_PREFET fail, step1) disable 'others', step2) disable P1V8 & P2V0, step 3) disable P1V0 [i.e. the reverse of the power-on sequence]
So next I want to resequence my rails in the event of a failure, ie if either P3V3_PREFET or PV_PWR go 'bad' and the rails sequence off, I then want to sequence them back on again once the incoming rail comes good again. I've experimented with the demo board and different combinations of the retry/resequence options but to no avail.
Any chance someone could give me some pointers to get this functionality in the GUI (either a step-by-step guide or by modifying my attached design) - I'm using V1.8.211 as the latest version seemed to crash lots...
I have no processor/PMBusMaster, the UCD90120 is operating without any external inputs.
Thanks in advance,
Bruce.
Hi Bruce,
You can explore our Re-Sequencing operation under the "Fault responses and Limits". You have not setup any fault responses for your system. All the faults are being ignored. You can set the rails to shutdown immediately or with delay or ignore the faults. Then you can enable "re-sequencing" which shuts the down and all the fault shut down slaves and tries to re-sequence all the rails. The start-up sequence would be followed during the re-sequencing. The re-sequencing options would be set up in the Other config tab.
Page 18 of the UCD90120A Datasheet explains this behavior. Also I have modified rail1 and rail2 of your project file as what I have mentioned.
Here is the project file
2476.xf07-523_2012-08-07_PowerOff_Current.xml