UM809 Datasheet, PDF (1/15 Pages) Union Semiconductor, Inc. – 3-Pin Microprocessor Reset Circuits

UM809/810
3-Pin Microprocessor Reset Circuits
UM809/810 SC70-3/SOT23-3
General Description
The UM809/810 series are ultra low current, cost effective system supervisory circuits designed to
monitor the power supplies in digital systems. They provide a reset signal to the host processor
when necessary, offer excellent circuit reliability & low cost by eliminating external component
and adjustment when used with +5V, +3.3V, +3.0V or other voltage powered circuits.
The reset output is driven active within 10 µs of power supply falling through the reset voltage
threshold. Reset is keeping active for a minimum of 140ms after system power supply has risen
above the reset threshold. Reset threshold suitable for operation with variety of supply voltage are
available.
UM809 has an active-low reset output while UM810 has an active-high reset output. The UM809
/ 810 are optimized to reject fast transient glitches on the power supply line, and the reset output
are guaranteed to be in the correct logic state for power supply V_CC down to 1V.
Each of these ICs consists of a voltage reference comparator, resistors for detector threshold
setting, delay generator, output driver & hysteresis circuit. The reset threshold & time delay are
fixed with high accuracy internally and does not require any external adjustment.
Low supply current of 3 µA (V_CC=3V) makes UM809/810 ideal for low power application. Both
devices are available in 3 Pin SC70 or SOT23 packages.
Applications
Features
 CPU and logic circuit Reset
 Power fail detector
 Computers
 Embedded system
 Battery powered equipment
 Intelligent instrument
 Wide operation voltage range of 1V to 10V
 Typical Quiescent current of 3μA
 No External components
 3-Pin small SC70 and SOT23 packages
 V_CC Transient immunity
 Correct logic output guaranteed to V_CC=1.0V
 Precision V_CC monitor for 2.5V, 3.0V, 3.3V,
and 5.0V supplies
 Available in 2 output configurations
Push-pull low active Reset output(UM809)
Push-pull high active Reset output(UM810)
 Wide operation Temperature: -40℃ to 105℃
Pin Configurations
Top View
Top View
Top View
UM809/810
M: Monthly Code
SC70-3/SOT23-3
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http://www.union-ic.com Rev.04 Dec.2013
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