SLUSEG4B December 2022 – February 2024 BQ25628 , BQ25629
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
When the BQ25628 is in bypass OTG mode, Q1 is off to block power from PMID to VBUS. BQ25628 uses two comparators to sense OVP. The PMID_OTG_OVP comparator monitors for an overvoltage condition at PMID (VPMID > VBYPASS_PMID_OVP.) The VBUS_OTG_OVP comparator monitors for an overvoltage condition at VBUS (VVBUS > VOTG_VBUS_OVP.) Even though RBFET is turned off during OTG mode on the BQ25628, an overvoltage at VBUS may result in an overvoltage at PMID via propagation across the RBFET body diode.
If an overvoltage persists on VBUS BQ25628 exits bypass OTG by setting EN_OTG = EN_BYPASS_OTG = 0.
If overvoltage persists on PMID bypass OTG is suspended, and the device enters hiccup mode. If the device cannot recover from hiccup mode, bypass OTG mode is exited by setting EN_OTG = EN_BYPASS_OTG = 0.
If VVBUS > VBAT+VSLEEP, BQ25628 will exit bypass OTG and enter adapter qualification. If VBUS passes adapter qualification (poor source detection), it will then enter forward charging mode. Even though the VVBUS > VOTG_OVP overvoltage condition does not cause an exit from bypass OTG, an adapter plugin will trip the longer deglitch of the sleep comparator, and BQ25628 will exit from bypass OTG for this reason.