TS2208A/B

The TS2208A/B series are over-charge/discharge protection ICs for rechargeable one-cell Lithium-ion batteries. They
bear an over-charge/over-discharge threshold for the battery cell voltage during charging/discharging process, and also provide on-time protection when excess current or short circuit occurs.  

The TS2208A/B series are essentially composed of a reference unit and three voltage detectors. During charging  process, when the cell voltage/V_DD crosses the over-charge threshold voltage VC1, the over charge detector (COM1) will switch the output pin (COUT) to a low  level within a delay time (t_C1), and thus turning off the MOSFET connected to the  charging path. The C_OUT pin may change to high level again when the V_DD voltage falls below "V_C1-V_HYS", or when V_DD falls below V_C1 while the charger is disconnected from the battery pack.  

During the discharging process of the TS2208A/B, when the VDD voltage crosses the over-discharge threshold voltage (V_D1), the   over-discharge detector (COM2) will switch DOUT to low level within a delay time (t_D1), and thus  turning  off  the MOSFET  connecting the discharging path. In the mean time, the TS2208A/B series will enter a low current standby mode. Once  into standby mode, it can only be released from standby after the battery pack is connected to a charger.  
The conditions of excess current and short circuit protection are both determined according to the voltage at the V-pin.

As the voltage of V- pin reaches a greater value than VOC, which means an undesirable large current is flowing through the path, DOUT will be switched to a low level and the path is cutoff after internally pre-set delay time (tOC) elapses. In  the case of short circuit, i.e. V- rises above VSHORT, the path will also be cutoff but with almost no delay time. Once the excess current or short circuit fault is removed, the built-in resistor at the V- pin, typically 100kohm, will pull V- down to VSS and bringing the IC back to normal operation.  
Together with the application circuit, the TS2208A/B will function as a consummate protector for Li-ion battery packs
which leads to safety and long lifetime.