YB1880
Standalone Linear Lithium Battery Charger
Function Block
Operation
The YB1880 is a single cell lithium-ion battery charger using a constant-current/constant-voltage algorithm. It
can deliver up to 800mA of charge current (using a good thermal PCB layout) with a final float voltage
accuracy of ±1%. The YB1880 includes an internal P-channel power MOSFET and thermal regulation circuitry.
No blocking diode or external current sense resistor is required; thus, the basic charger circuit requires only
two external components. Furthermore, the YB1880 is capable of operating from a USB power source.
Normal Charge Cycle
A charge cycle begins when the voltage at the VCC pin rises above the UVLO threshold level and a 1%
program resistor is connected from the PROG pin to ground or when a battery is connected to the charger
output. If the BAT pin is less than 2.8V, the charger enters trickle charge mode. In this mode, the YB1880
supplies approximately 1/10 the programmed charge current to bring the battery voltage up to a safe level for
full current charging. When the BAT pin voltage rises above 2.8V, the charger enters constant-current mode,
where the programmed charge current is supplied to the battery. When the BAT pin approaches the final float
voltage (4.2V), the YB1880 enters constant-voltage mode and the charge current begins to decrease. When
the charge current drops to 1/10 of the programmed value, the charge cycle ends.
YB1880 Rev.1.0
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YOBON [ YOBON TECHNOLOGIES,INC. ]
