Data Sheet

Precharge
Phase
Constant Current
Phase
Constant Voltage
Phase
Charge terminated
Charge Current
Battery Voltage
3V
4.2V
Figure 4 Charging Profile
Application Information
Undervoltage Lockout (UVLO)
An internal undervoltage lockout circuit monitors the input voltage and keeps the charger in shutdown mode
until V
IN
rises above the undervoltage lockout voltage. The UVLO circuit has a built-in hysteresis of 0.1V.
Sleep mode
There is an on-chip sleep comparator. The comparator keeps the charger in sleep mode if V
IN
falls below sleep
mode threshold(VBAT+40mv). Once in sleep mode, the charger will not come out of sleep mode until V
IN
rises
90mv above the battery voltage.
Precharge mode
At the beginning of a charge cycle, if the battery voltage is below 3V, the charger goes into precharge mode ,
and the charge current is 10% of fast charge current in constant current mode.
Charging Current limited by the Output capability of Input Power Supply
If the output capability of input power supply is less than the charging current set by the resistor at ISET pin,
then the on-chip 8-bit ADC will begin to function to adjust the charging current based on the output capability
of input power supply. In this case, the charging current may be less than the value set by the resistor at ISET
pin, but it is maximized to the output capability of input power supply on the condition that the input voltage at
VIN pin is no less than 4.35V, which is the minimum operating voltage of CN3083. So the charging current can
be set according to the maximum output capability of input power supply, not the worst case.
Adjusting the regulation voltage in constant voltage mode
The regulation voltage in constant voltage mode can be adjusted by an external resistor connecting between FB
pin and BAT pin as shown in Figure 5:
REV 1.1 7