ELM365
Pin Descriptions
VDD (pin 1)
LED (pin 5)
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.
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.
OutP (pin 2)
ILoop (pin 6)
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.
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.
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.
DLoop (pin 7)
panic (pin 4)
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.
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).
VSS (pin 8)
Circuit common is connected to this pin. This is
the most negative point in the circuit.
Ordering Information
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
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.
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ELM365DSB
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