When the main charger is in OTG or reverse TX
Mode, the input power MUX (ACFET-RBFET) also controls which port is desired for OTG
output.
To enter OTG or reverse TX Mode, the host should
follow the steps below:
- Host writes EN_OTG =1
- BQ25960H sets DIS_ACDRV_BOTH =1
- Host writes DIS_ACDRV_BOTH=0, and then writes ACDRV1_STAT=1 or ACDRV2_STAT=1 depending on which port is desired for OTG or reverse TX output
- Host enables OTG Mode on main charger
- If VBUSOVP or VACOVP fault occurs, ACDRV will be disabled but EN_OTG is still
'1'. Host needs to write ACDRV1_STAT high or ACDRV2_STAT high when the fault is
cleared. Set VAC1OVP and VAC2OVP to the same threshold in the OTG Mode
- EN_OTG is cleared when watchdog timer expires
To exit OTG or Reverse TX Mode, the host should
follow the steps below:
- Turn off main OTG or reverse TX source
- Turn on VBUS pulldown resistor (RVBUS_PD) by setting BUS_PD_EN=1 or
VAC pulldown resistor RVAC_PD by setting VAC1_PD_EN=1 or
VAC2_PD_EN=1, depending on which port is to be discharged
- Wait for VBUS and VAC to be discharged
- Turn off ACDRV by setting ACDRV1_STAT=0 or ACDRV2_STAT=0
- Exit OTG Mode by setting EN_OTG=0