Tool/software:
Setup notes (for context only): Back-to-back N-MOSFETs as BATFET (source-to-source), BATDRV driving the gates, optional capacitor between BATDRV and BATSRC. VSYS has load 20W.
Observed behavior
No RC (no soft-start) between BATDRV and BATSRC
When enabling BATFET with load present on VSYS, the hand-off VBAT→VSYS fails: over-current protection is triggered and the path shuts down. A reset is required to recover.
With RC soft-start (capacitor from BATDRV to BATSRC)
The VBAT→VSYS hand-off under load succeeds. No OCP trip is observed.
With the same RC soft-start, when VAC is plugged in (adapter re-applied) while load remains on VSYS
The device transitions to forward operation (BATFET OFF, ACFET ON). During/after this transition the BATFET is damaged (burned).