FUJITSU SEMICONDUCTOR
DATA SHEET
DS04-27703-4E
ASSP
For Power Supply Applications (Lithium ion battery charger)
DC/DC Converter IC for Charging
MB3875/MB3877
s
DESCRIPTION
The MB3875 and MB3877 are charging DC/DC converter ICs suitable for down-conversion, which uses pulse
width modulation (PWM) for controlling the output voltage and current independently.
These ICs can dynamically control the secondary battery’s charge current by detecting a voltage drop in an AC
adapter in order to keep its power constant (dynamically-controlled charging).
The charging method enables quick charging, for example, with the AC adapter during operation of a notebook PC.
With an on-chip output voltage setting resistor which allows the output voltage to be set at high precision, these
ICs are best suited as internal battery chargers for notebook PCs.
The MB3875 and MB3877 support 3-cell and 4-cell batteries, respectively.
These products are covered by US Patent Number 6,147,477.
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FEATURES
• Detecting a voltage drop in the AC adapter and dynamically controlling the charge current (Dynamically-con-
trolled charging)
• High efficiency : 95 %
• Wide range of operating supply voltages: 7 V to 25 V
• Output voltage precision (Output voltage setting resistor integrated): 0
±
0.8 % (Ta =
+
25
°C)
(Continued)
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PACKAGE
24-pin plastic SSOP
(FPT-24P-M03)
FUJITSU [ FUJITSU COMPONENT LIMITED. ]
