ZHCSN83A june 2020 – january 2021 BQ25731
PRODUCTION DATA
During converter steady state operation VSYS pin is monitoring the system voltage, when VSYS is lower than 1.6 V, there is 2-ms deglitch time, the IIN_DPM is set to 0.5 A by the charger itself. After 2-ms deglitch time, the charger should shut down and latched off. Fault VSYS_UVP bit will be set to 1 to report a system short fault. The charger only can be enabled again once the host writes Fault VSYS_UVP bit to 0b.
During converter startup after VBUS rise above VVBUS_CONVEN: when VSYS is lower than 1.6 V, the IIN_DPM is set to 0.5 A by the charger itself. After VSYS rise up higher than 1.6-V threshold IIN_DPM will be released to default charger IIN_DPM setting. If after converter startup for 3 min (BQ25731), VSYS is still lower than 1.6-V threshold, then the charger should shut down and latched off. Fault VSYS_UVP bit will be set to 1 to report a system short fault. The charger only can be enabled again once the host writes Fault VSYS_UVP bit to 0b.
The charger VSYS_UVP is enabled by POR and can be disabled by writing VSYS_UVP_ENZ=1b.