XC6802_15 Datasheet, PDF (5/21 Pages) Torex Semiconductor – 800mA Single Cell Li-ion Battery Linear Charger IC

˙OPERATIONAL EXPLANATION
Charge Cycle
(Charge Main Routine)
Trickle Charge
Constant-Current Charge (CC)
Constant-Voltage Charge (CV)
Yes
Keeping the charge state
during a charge termination
detect time (1ms)
Charge Termination
(Stand-by Mode)
Input Voltage Monitor (UVLO)
Charge Cycle
Shut-down
Yes
Keeping the stand-by mode
during a recharge time
(2ms)
Failure Detection
Manual Shut-down
Charge Cycle
Shut-down
XC6802
Series
V_IN-BAT Voltage Monitor
Charge Cycle
Shut-down
<Charge Cycle>
If the BAT pin voltage is less than trickle voltage (TYP. 2.9V), the charger enters trickle charge mode. In this mode, a safe
battery charge is possible because approximately only 1/10 of the charge current which was set by the I_SEN pin, is supplied to
the battery. When the BAT pin voltage rises above the trickle voltage, the charger enters constant-current mode (CC mode)
and the battery is charged by the programmed charge current. When the BAT pin voltage reaches 4.2V, the charger enters
constant-voltage mode (CV mode) automatically. After this, the charge current starts to drop and when it reaches a level
which is 1/10 of the programmed charge current, the charge terminates.
<Setting Charge Current>
The charge current can be set by connecting a resistor between the I_SEN pin and the V_SS pin. The battery charge current, I_BAT,
is 1000 times the current out of the I_SEN pin. Therefore, the charge current, I_BAT, is calculated by the following equations:
I_BAT = (V_ISEN / R_SEN) x 1000 (V_ISEN = 1.0V (TYP.): Current sense pin voltage)
However I_BATʽ800mA (SOT-25, SOT-89-5, and USP-6C), I_BATʽ500mA (USP-6EL)
<Charge Termination>
The battery charge is terminated when the charge current decreases to 1/10 of the full charging level after the battery pin
voltage reaches a float voltage. An internal comparator monitors the I_SEN pin voltage to detect the charge termination. When
the comparator monitors the I_SEN pin voltage is less than 100mV (charge termination detect) ^(*1) for 1ms TYP. (charge
termination detect time), the IC enters stand-by mode. A driver transistor turns off during the stand-by mode. In this state, a
failure detection circuit and a monitoring circuit of the battery pin voltage operates.
(*1) _{The detect after charging completed: ISEN pin voltage should be less than 100mV.}
<Automatic Recharge>
In stand-by mode battery voltage falls. When the voltage level at the battery pin drops to recharge battery threshold voltage
(TYP. 4.05V) or less, the charge cycle automatically re-starts after a delay of (TYP. 2ms). As such, no external activation
control is needed.
5/21