Prior to enabling charging, set all the protections to the desired thresholds. Protections available are BAT_OVP, BAT_OVP_ALM, BAT_OCP, BAT_OCP_ALM, BAT_UCP_ALM, AC_PROTECTION, BUS_OVP, BUS_OVP_ALM, BUS_OCP_UCP, and BUS_OCP_ALM. These can be found in registers 0x0h through 0x9h. The *_OVP and *_OCP registers set the thresholds where if these conditions are met, the charger stops switching. The *_ALM registers set the thresholds where an interrupt is sent to the host to take actions to avoid reaching the *_OVP or *_OCP thresholds. The settings for the *_ALM registers will depend on the response time required from the host and the operating conditions of the system.

Once the protections have been set, the BUS voltage must be between VBUS_ERROR_LO and VBUS_ERROR_HI in order for the part to start switching. Register 0x0Ah contains the registers to check if these conditions have been met. Typically VBUS_ERROR_LO is 2.05 times VBAT. It is recommended to start with VBUS near this voltage when enabling charge. Once charge has been enabled, the CONV_SWITCHING_STAT bit should be '1', and current will start to flow to the battery. Raising the BUS voltage will increase the current to the battery. If using a current limited source, the voltage can be raised until reaching the current limit. The battery current, IBAT, must reach the IBUS_UCP_THRESHOLD rise threshold within the SS_TIMEOUT_SET time. These parameters can be set in register 0x2Bh. If the IBUS_UCP_THRESHOLD is not met within SS_TIMEOUT_SET, switching stops and the startup sequence must be done again.