Once the OUT pin goes above VRCH, (reaches voltage regulation) and the current tapers down to the termination threshold, the CHG pin goes high impedance and a battery detect route is run to determine if the battery was removed or the battery is full. If the battery is present, the charge current terminates. If the battery was removed along with the thermistor, then the TS pin is driven high and the charge enters TTDM. If the battery was removed and the TS pin is held in the active region, then the battery detect routine continues until a battery is inserted.