YB1880 Datasheet, PDF (2/10 Pages) YOBON TECHNOLOGIES,INC. – Standalone Linear Lithium Battery Charger

Pin Configuration
YB1880
Standalone Linear Lithium Battery Charger
Figure 2: Pin Configuration
Pin Description
Table 1
Pin Number
1
2
3
4
Pin Name
CHRG
GND
BAT
VCC
Description
Open-Drain Charge Status Output. When the battery is charging, the CHRG pin is
pulled low by an internal N-channel MOSFET. When the charge cycle is completed,
a weak pull-down of approximately 20mA is connected to the CHRG pin, indicating
an “AC present” condition. When the YB1880 detects an under voltage lockout
condition, CHRG is forced high impedance.
Ground
Charge Current Output. Provides charge current to the battery and regulates the
final float voltage to 4.2V. An internal precision resistor divider from this pin sets the
float voltage which is disconnected in shutdown mode.
Positive Input Supply Voltage. Provides power to the charger. VCC can range from
4.25V to 6.5V and should be bypassed with at least a 1mF capacitor. When VCC
drops to within 30mV of the BAT pin voltage, the
YB1880 enters shutdown mode, dropping IBAT to less than 2mA.
Charge Current Program, Charge Current Monitor and Shutdown Pin. The charge
current is programmed by connecting a 1% resistor, RPROG, to ground. When
charging in constant-current mode, this pin servos to 1V. In all modes, the voltage
on this pin can be used to measure the charge current using the following formula:
IBAT = (VPROG/RPROG) • 1000
5
PROG
The PROG pin can also be used to shut down the charger. Disconnecting the
program resistor from ground allows a 3mA current to pull the PROG pin high.
When it reaches the 1.21V shutdown threshold voltage, the charger enters
shutdown mode, charging stops and the input supply current drops to 25mA. This
pin is also clamped to approximately 2.4V. Driving this pin to voltages beyond the
clamp voltage will draw currents as high as 1.5mA. Reconnecting RPROG to
ground will return the charger to normal operation.
Ordering Information
Order Number Package Type
YB1880ST25P
SOT23-5
Supplied As
3000 units Tape & Reel
Package Marking
Please contact sales
representative
YB1880 Rev.1.0
www.yobon.com.tw
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