ELM ELM365SM, ELM365P Datasheet
ELM365
1234876
5
Security System Controller
235
Description
467
Features
The ELM365 provides all of the logic necessary
for a complete security system in an 8 pin package.
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.
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.
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.
Applications
• Home or cottage security systems
• Auto or RV security systems
• Individual zone monitoring in a multizone system
• High or low limit warning alarms
• 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
• Automatic reset of alarm outputs after 5 minutes
• Status LED output driver
• High current drive outputs - up to 25 mA
• Panic input for instant triggering of the alarm
Connection Diagram
PDIP and SOIC
(top view)
VDD VSS
DLoopOutP
OutC
panic
ILoop
LED
Block Diagram
DLoop
ILoop
panic
ELM365DSB
VDD
VDD
VDD
45 sec
Delay
45 sec
PowerUp
Alarm
Latch
Alarm
Latch
5 min
Reset
fast
slow
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LED
Flasher
1.5s on
0.5s off
LED
OutC
OutP
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ELM365
Pin Descriptions
VDD (pin 1)
This pin is the positive supply pin, and should
always be the most positive point in the circuit.
Internal circuitry connected to this pin is used to
provide power on reset of the microprocessor, so
an external reset signal is not required. Refer to
the Electrical Characteristics section for further
information.
OutP (pin 2)
This is the (active high) pulsed alarm output.
When in an alarm state, it alternates between a
logic high level (VDD) for 1.5 seconds and a low
level (VSS) for 0.5 seconds. This output
automatically resets after 5 minutes.
OutC (pin 3)
This is the constant level alarm output. It is
switched to a high level (VDD) during an alarm
condition, and is otherwise at a logic low level.
This output automatically resets to a low level
after 5 minutes.
panic (pin 4)
This active low input is debounced and used to
immediately trigger an alarm from normally open
inputs such as panic pushbuttons or tamper
switches. If unused, this input can be left open
circuited, as there is an internal pullup resistor on
the pin (see the specs).
LED (pin 5)
This is an active low LED drive output. It will
pulse rapidly to warn that the system is in a 45
second delayed alarm period, or will pulse slowly
(about 1.5 seconds on, 0.5 seconds off) if an
alarm is in progress or has previously occurred.
By adding a suitable series resistor, an LED can
be directly driven from this pin.
ILoop (pin 6)
This pin is used for monitoring a normally closed
loop, connected between the pin and VSS. To
reduce the possibility of nuisance triggers, a 0.5
second debounce period is provided on this input.
An alarm will be initiated immediately after the
loop is determined to be open, but will not
retrigger an alarm if the loop remains open, after
the five minute timeout. This pin is not enabled for
the first 45 seconds after the system is first turned
on.
DLoop (pin 7)
This pin is similar to pin 6, with the one exception
being that the alarm is delayed by 45 seconds to
allow time for entry or exit.
VSS (pin 8)
Circuit common is connected to this pin. This is
the most negative point in the circuit.
Ordering Information
All rights reserved. Copyright ©1999 Elm Electronics.
Every effort is made to verify the accuracy of information provided in this document, but no representation or warranty can be
given and no liability assumed by Elm Electronics with respect to the accuracy and/or use of any products or information
described in this document. Elm Electronics will not be responsible for any patent infringements arising from the use of these
products or information, and does not authorize or warrant the use of any Elm Electronics product in life support devices and/or
systems. Elm Electronics reserves the right to make changes to the device(s) described in this document in order to improve
reliability, function, or design.
ELM365DSB
These integrated circuits are available in either the 300 mil plastic DIP format, or in the 200 mil SOIC surface
mount type of package. To order, add the appropriate suffix to the part number:
300 mil Plastic DIP............................... ELM365P 200 mil SOIC.....................................ELM365SM
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