ZHCSI59I July 2009 – May 2018 TPS65070 , TPS65072 , TPS65073 , TPS650731 , TPS650732
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
Whenever the battery voltage falls below VRCH (Vset-100 mV), a check is performed to see whether the battery has been removed: current IBAT(DET) is pulled from the battery for a duration tDET. If the voltage on the BAT pin remains above VLOWV, it indicates that the battery is still connected. If the charger is enabled by Bit CHARGER ENABLE in register CHGCONFIG1 set to 1, the charger is turned on again to top up the battery.
If the BAT pin voltage falls below VLOWV in the battery detection test, it indicates that the battery has been removed. The device then checks for battery insertion: it turns on FET Q2 and sources IPRECHG out of the BAT pin for duration tDET. If the voltage does not rise above VRCH, it indicates that a battery has been inserted, and a new charge cycle can begin. If, however, the voltage does rise above VRCH, it is possible that a fully charged battery has been inserted. To check for this, IBAT(DET) is pulled from the battery for tDET: if the voltage falls below VLOWV, a battery is not present. The device keeps looking for the presence of a battery.