MB39A125 Datasheet, PDF (35/64 Pages) Fujitsu Component Limited. – DC/DC Converter IC for Charging Li-ion Battery

MB39A125/126
(2) Automatic changing system power supply between AC adapter and battery
The AC adapter voltage is detected and external switch at input side and battery side can be changed automat-
ically with the connection as follows. Connect CTL terminal (pin 14) to VCC terminal (pin 21) for this function.
OFF duty cycle becomes 100% when CS terminal (pin 22) voltage is made to be 0 V, if it is needed after full charge.
• Connection example of automatic changing system power supply between AC adapter and battery
System
AC adapter
ACIN
7
<AC Comp.>
+
−
ACOK
5
XACOK
18
micon
VCC
21
CTL ₁₄
< SOFT>
VREF
CS
22
10 µA
Battery
35