DS04-27400-11E

FUJITSU SEMICONDUCTOR

DATA SHEET

Copyright©2003-2006 FUJITSU LIMITED All rights reserved

ASSP For power supply applications

BIPOLAR

Power Supply Monitor

MB3771

■ DESCRIPTION

The Fujitsu MB3771 is designed to monitor the voltage level of one or two power supplies (+5 V and an arbitrary

voltage) in a microprocessor circuit, memory board in large-size computer, for example.

If the circuit’s power supply deviates more than a specified amount, then the MB3771 generates a reset signal to

the microprocessor. Thus, the computer data is protected from accidental erasure.

Using the MB3771 requires few external components. To monitor only a +5 V supply, the MB3771 requires the

connection of one external capacitor. The level of an arbitrary detection voltage is determined by two external

resistors. The MB3771 is available in an 8-pin Dual In-Line, Single In-Line Package or space saving Flat Package.

■ FEATURES

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• Monitors the voltage of one or two power supplies (5 V and an arbitrary voltage, >1.23 V)

• Usable as over voltage detector

• Minimal number of external components (one capacitor Min)

• Detection threshold voltage has hysteresis function

• Reference voltage is connectable.

• One type of package (SOP-8pin : 1 type)

■ APPLICATION

• Industrial Equipment

• Arcade Amusement

etc.