FUJITSU SEMICONDUCTOR
DATA SHEET
DS04-27229-2E
ASSP
For Power Supply Applications (General Purpose DC/DC Converter)
2-Channel DC/DC Converter IC
with Overcurrent Protection Symmetrical-Phase Type
MB3889
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DESCRIPTION
The MB3889 is a symmetrical-phase type of two-channel, DC/DC converter IC using pulse width modulation
(PWM) , incorporating an overcurrent protection circuit (requiring no current sense resistor) and an overvoltage
protection circuit. Providing high output driving capabilities, the MB3889 is suitable for down-conversion.
The MB3889 adopts both synchronous rectification to provide high efficiency and symmetrical phasing (two anti-
phase triangular waves) which contributes to making the input capacitor small.
The MB3889 contains a 5-volt regulator resulting in a reduced number of components used. It also contains a
variety of protection features which output the protection status upon detection of an overvoltage or overcurrent
while reducing the number of external protective devices required.
The result is an ideal built-in power supply for driving products with high speed CPU’s such as home TV game
devices and notebook PC’s.
This product is covered by US Patent Number 6,147,477.
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FEATURES
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Built-in timer-latch overcurrent protection circuit (requiring no current sense resistor)
Built-in timer-latch overvoltage protection circuit
Synchronous rectification system providing high efficiency
Power supply voltage range: 5.5 V to 18 V
PWRGOOD terminals (open-drain) to output the protection status
Symmetrical-phase system reducing the input capacitor loss
Built-in channel control function
Reference voltage: 3.5 V
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1
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PACKAGE
30-pin plastic TSSOP
(FPT-30P-M04)
FUJITSU [ FUJITSU COMPONENT LIMITED. ]
