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http://www.union-ic.com Rev.01 Jan.2015

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UM805/811/812

4-Pin μP Voltage Monitors with Manual Reset Input

UM805/811/812 SOT143

General Description

The UM805/811/812 are low-power microprocessor (μP) supervisory circuits used to monitor power

supplies in μP and digital systems. They provide excellent circuit reliability and low cost by

eliminating external components and adjustments when used with 5V-powered or 3V-powered

circuits. The UM805/811/812 also provide a debounced manual reset input.

reset threshold. Reset thresholds are available for operation with a variety of supply voltages.

The UM805 has an open-drain output stage, while the UM811/812 have push-pull outputs. The

UM805’s open-drain RESET

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output requires a pull-up resistor that can be connected to a voltage

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output, while the UM812 has an

Low supply current makes the UM805/811/812 ideal for use in portable equipments. The devices

come in a 4-pin SOT143 package.

Applications

Features

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Computers

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Controllers

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Portable/Battery-Powered Equipments

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Intelligent Instruments

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Critical μP and μC Power Monitoring

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No External Components

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Supplies

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2μA Supply Current

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140ms Minimum Power-On Reset Pulse Width

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Guaranteed Over Temperature

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Available in 3 Output Configurations:

Open-Drain Active-Low RESET

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Output(UM805)

Push-Pull Active-Low RESET

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Output(UM811)

Push-Pull Active-High RESET Output(UM812)

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4-Pin SOT143 Package

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Wide Operation Temperature: -40°C to +85°C