ELM365
Security System Controller
Description
Features
The ELM365 provides all of the logic necessary
for a complete security system in an 8 pin package.
• Low power CMOS design - typically 1mA at 5V
• Wide supply range - 3.0 to 5.5 volt operation
• Simultaneous monitoring of three circuits
• 45 second delay for entry and exit
The circuit is capable of monitoring two normally
closed input loops and one normally open panic
circuit, provides a constant level and a pulsing alarm
output, and the logic to drive a status LED.
• Automatic reset of alarm outputs after 5 minutes
• Status LED output driver
Internal timers are provided for alarm blocking
during zone entry and exit as well as circuit
resetting, should alarms go unacknowledged.
Debouncing of all of the inputs is also provided
internally, to allow for the direct interfacing to
mechanical switches.
• High current drive outputs - up to 25 mA
• Panic input for instant triggering of the alarm
Due to the digital techniques employed, no
external support components are required for any of
the timing functions, resulting in considerable cost
savings over other designs.
Connection Diagram
PDIP and SOIC
(top view)
Applications
1
2
3
4
8
7
6
5
VDD
OutP
OutC
panic
VSS
• Home or cottage security systems
• Auto or RV security systems
DLoop
ILoop
LED
• Individual zone monitoring in a multizone system
• High or low limit warning alarms
Block Diagram
VDD
DLoop
7
fast
45 sec
Delay
45 sec
PowerUp
LED
Flasher
5
LED
VDD
VDD
slow
ILoop
panic
6
4
Alarm
Latch
Alarm
Latch
3
2
OutC
OutP
1.5s on
0.5s off
5 min
Reset
ELM365DSB
Elm Electronics – Circuits for the Hobbyist
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