MB3879 参数 Datasheet PDF下载

FUJITSU SEMICONDUCTOR

DATA SHEET

DS04-27708-2E

ASSP

for Power Supply Application (for secondary battery)

DC/DC Converter IC for Parallel Charging

of 3/4 cell Li-ion & NiMH Batteries

MB3879

s

DESCRIPTION

The MB3879 is a DC/DC converter IC for parallel charging of 3/4 cell Li-ion & NiMH batteries, which uses the

pulse-width modulation (PWM) for controlling output voltages and output currents independently.

This IC can dynamically control secondary batterie’s charge current, which detects voltage dropping in an AC

adapter in order to keep its power constant (Dynamically controlled charging). This operation allows quick charging

by variable charging current in accordance with operating status of a notebook PC.

Moreover, the total current of the system current and control IC input current are detected, and control of the

secondary battery is enabled.

An efficient charge becomes possible because of the charge current comes in changeability according to the

operation state of notebook PC by this operation.

The IC also allows parallel charging that charges two batteries simultaneously, reducing charging time dramatically.

The IC, using a built-in output voltage setting resistor, allows high-precision setting of output voltages. With its

output-voltage switching function that is ready for both graphite-type and coke-type Li-ion batteries as well as

NiMH battery, the IC is best suited to a built-in charger of a notebook PC.

This product is covered by US Patent Number 6,147,477.

s

FEATURES

• Detecting a voltage dropping in the AC adapter, and dynamically controlling the charge current (Dynamically-

controlled charging)

• Detecting total current of system current and control-IC input current (Differential-charging)

(Continued)

48-pin plastic LQFP

s

PACKAGE

(FPT-48P-M05)