UM803RS-3引脚微处理器复位电路

KeySpecifications

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ProductDescription  

TheUM803 is a microprocessor (μP) supervisory circuit used to monitorthe power supplies in μP and digital systems. It provides excellentcircuit reliability and low cost by eliminating external componentsand adjustments when used with +5V, +3.3V, +3.0V or +2.5V poweredcircuits.

Thecircuit performs a single function: it asserts a reset signalwhenever the VCC supply voltage declines below apreset threshold, keeping it asserted for at least 140ms afterVCC has risen above the reset threshold. Resetthresholds suitable for operation with a variety of supply voltagesare available.

TheUM803 has an open-drain output stage. The UM803’sopen-drain RESET(_______________) output requires apull-up resistor that can be connected to a voltage higher thanVCC. The UM803 has anactive-low RESET(_______________) output. The resetcomparator is designed to ignore fast transients on VCC,and the outputs are guaranteed to be in the correct logic state forVCC down to 1V.

Lowsupply current makes the UM803 ideal for use in portable equipment.The UM803 is available in a 3-pin SOT323 and SOT23package.

Features

-No External Components

-Power Supply Transient Immunity

-Guaranteed Reset Valid to VCC=+1V

-Precision VCC Monitoring of +2.5V, +3V, +3.3V and+5V Supplies

-Fully Specified Over Temperature

-2μA Supply Current

-140ms Minimum Power-On Reset Pulse Width

-Available in One Output Configuration:

 Open-DrainActive-Low RESET(_______________) Output

-3-Pin SOT323 and SOT23 Packages

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

TypicalApplication Circuit

Applications

-Computers

-Controllers

-Portable/Battery-Powered Equipments

-Intelligent Instruments

-Critical μP and μC Power Monitoring

-Automotive

PinConfigurations  

OrderingInformation

UM8 XX Z P

XX:Output Type

=03   Open-Drain Active Low

Z:Reset Threshold (V)

=L      4.63

=M     4.38

=J      4.00

=T      3.08

=S      2.93

=R      2.63

=Z      2.32

P:Package Type

=S     SOT23-3

=P      SOT323

SelectionTable