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FEATURES DESCRIPTION
BLOCK DIAGRAM
Note: Pin numbers refer to J, N and DW packages.
UC1903
UC2903
UC3903
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........................................................................................................................................ SLUS233A – OCTOBER 1999 – REVISED SEPTEMBER 2008
Quad Supply and Line Monitor
• Inputs for Monitoring up to Four Separate
The UC1903 family of quad supply and line monitor
Supply Voltage Levels
integrated circuits will respond to under- and
over-voltage conditions on up to four continuously
• Internal Inverter for Sensing a Negative Supply
monitored voltage levels. An internal op-amp inverter
Voltage
allows at least one of these levels to be negative. A
• Line/Switch Sense Input for Early Power
separate line/switcher sense input is available to
Source Failure Warning
provide early warning of line or other power source
• Programmable Under- and Over-Voltage Fault
failures.
Thresholds with Proportional Hysteresis
The fault window adjustment circuit on these devices
• A Precision 2.5-V Reference
provides easy programming of under- and
over-voltage thresholds. The thresholds, centered
• General Purpose Op-Amp for Auxiliary Use
around a precision 2.5-V reference, have an input
• Three High Current, >3 0mA, Open-Collector
hysteresis that scales with the window width for
Outputs Indicate Over-Voltage, Under-Voltage
precise, glitch-free operation. A reference output pin
and Power OK Conditions
allows the sense input fault windows to be scaled
• 8-V to 40-V Supply Operation with 7-mA
independently using simple resistive dividers.
Stand-By Current
The three open collector outputs on these devices
sink in excess of 30 mA of load current when active.
The under- and over-voltage outputs respond after
separate, user defined, delays to respective fault
conditions. The third output is active during any fault
condition including under- and over-voltage,
line/switcher faults, and input supply under-voltage.
The off state of this output indicates a "power OK"
situation.
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Copyright © 1999 – 2008, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
