MB3877

FUJITSU SEMICONDUCTOR DATA SHEET DS04-27703-2E 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. s FEATURES Detecting a voltage drop in the AC adapter and dynamically controlling the charge current (Dynamically-controlled 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) High precision reference voltage source : 4.2 V ± 0.8 % (Continued) s PACKAGE 24-pin plastic SSOP (FPT-24P-M03) MB3875/MB3877 (Continued) Support for frequency setting using an external resistor (Frequency setting capacitor integrated) :100 kHz to 500 kHz ...