Questions from customer
Symptomatology
The output of REGN = 4.8V stopped. (Output only for a short time when VBUS is turned on)
It seems that the output of REGN has dropped when VSYS is about to start up.
* Waveforms are attached for your reference.
What is the cause of this?
What I did as an operation check (what I was able to check when it was working without problems)
・ VBUS = 5V was input and REGN = 4.8V was output.
・ VBUS = 5V was input and VSYS = 8.4V was output.
=> At this time, I touched the register settings on the TI Charger GUI, changed the settings to VSYS = 8.2V and VSYS = 8.0V, and confirmed that they were actually output.
・ When VBAT = 8.2V was input without inputting anything to VBUS, VSYS = 8.2V was output (at this time, VSYS has no load).
I checked if EN_HIZ was set. (Watchdog is disable.)
When I looked at the EN_HIZ check box on the TI Charger GUI, it was checked.
When unchecked, it was confirmed that an attempt was made to temporarily output REGN as shown in the attached waveform. (It drops repeatedly from 0V to 5V for about 3.5 seconds.)
Regards,
Kagawa
