UTC LM1851
LINEAR INTEGRATED CIRCUIT
GROUND FAULT INTERRUPTER
DESCRIPTION
The UTC LM1851 is designed to provide ground fault
protection for AC power outlets in consumer and industrial
environments. Ground fault currents greater than a presentable
threshold value will trigger an external SCR-driven circuit
breaker to interrupt the AC line and remove the fault condition.
In addition to detection of conventional hot wire to ground faults,
the neutral fault condition is also detected.
Full advantage of the U.S. UL943 timing specification is taken
to insure maximum immunity to false triggering due to line noise.
Special features include circuitry that rapidly resets the timing
capacitor in the event that noise pulses introduce unwanted
charging currents and a memory circuit that allows firing of even
a sluggish breaker on either half-cycle of the line voltage when
external full-wave rectification is used.
DIP-8
SOP-8
FEATURES
* Internal power supply shunt regulator
* Externally programmable fault current threshold
* Externally programmable fault current integration time
* Direct interface to SCR
* Operates under line reversal; both load vs line and hot
vs neutral
* Detects neutral line faults
PIN CONFIGURATION
SCR Trigger
INVERTING INPUT
NON-INVERTING INPUT
GND
1
2
3
4
8
7
6
5
Vcc
TIMING CAPACITOR
SENSE ITIVITY SET RESISTOR
SENSE AMPLIFIER OUTPUT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
1
QW-R122-007,A
UTC-IC [ UNISONIC TECHNOLOGIES ]
