SLUSA75B July 2010 – January 2020 BQ24650
The BQ24650 uses a SLEEP comparator to determine the source of power on the VCC pin, because VCC can be supplied either from a battery or an adapter. If the VCC voltage is greater than the SRN voltage, and all other conditions are met for charging, the BQ24650 then attempts to charge a battery (see Enable and Disable Charging). If SRN voltage is greater than VCC, indicating that a battery is the power source, the BQ24650 enters low quiescent current (< 15 µA) SLEEP mode to minimize current drain from the battery.
If VCC is below the UVLO threshold, the device is disabled, and VREF LDO turns off.