FS8530 Vpre Not Output

[jhhan]

HI~

Now I use FS8530 PMIC
VBOS => VPRE => VBoost => BUCK1/BUCK2/BUCk3/LDO1/LDO2
The power supply operates normally with the WakeUP 1 signal.
I have a problem.
When powered off, change the PMIC to GotoStandby.
However, if the Wakeup1 signal occurs due to quick power application,

the Vpre power is not output. (Most normal working)
Current register settings changes, do not solve the problem.
I would appreciate it if you could let me know if there is a solution.

[guoweisun]

HI 

Please help and check whether you match below red circled conditions to turn on Vpre:

[jhhan]

Thank you for your quick response.

1. Wake1 = '1' DBG = '0' , I think go to Next

2. VSUP > VSUP_uvh: OK

  VBOS > VBOS_uvh : OK

I don't know the condition that FS_READY '1'

Psync is '0' when measured with an oscilloscope.

The OTP setting is shown in the attached figure.

[guoweisun]

 FS_READY '1' means A synchronization between Main and Fail safe state machines, which is indeed VSUP > VSUP_UVH and WAKE1
or WAKE2 > WAKE12VIH, and LBIST has been executed

[jhhan]

attached figure