ELM624
Control L and LANC
The terms Control L and LANC mean the same thing, and are used interchangeably throughout the following.
Pin Descriptions
VDD (pin 1)
Rx (pin5)
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.
The computer’s RS232 transmit signal is directly
connected to this pin through a single current limiting
resistor (typically about 47KW). Internal signal
inversion and Schmitt trigger waveshaping provide
the necessary signal conditioning.
Tx (pin 6)
XT1 (pin 2) and XT2 (pin 3)
This is the RS232 data output pin. The signal
polarity is compatible with most interface ICs, and
the drive is sufficient to allow interfacing using only a
single PNP transistor if desired. See the Example
Applications section for more details.
A 3.579545MHz NTSC television colourburst crystal
is connected between these two pins. Crystal
loading capacitors (typically 27pF) will also normally
be connected between each of the pins and Vss.
When selected for Trigger Pulse outputs, this pin
provides the active low output pulses.
Note that this frequency is used for both 50Hz and
60Hz systems. The ELM624 automatically adjusts to
the system that you are using.
LANC (pin 7)
This is the open drain Control L (LANC) interface
pin. An internal pullup resistor is provided for a
nominal drain load.
Enable (pin 4)
This is an active high input that controls RS232 data
flow to and from the ELM624. If at a high level, the
RS232 data communications are enabled, while a
low input disables them. When disabled, all RS232
data sent to the IC is ignored, and no RS232 output
is generated by the ELM624. See the Example
Applications section for more on this.
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............................... ELM624P
200 mil SOIC..................................... ELM624SM
Control L, LANC, and Sony are registered trademarks of the Sony Corporation.
All rights reserved. Copyright 2004 by Elm Electronics Inc.
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 Inc. with respect to the accuracy and/or use of any products or information
described in this document. Elm Electronics Inc. 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 Inc. product in life support devices
and/or systems. Elm Electronics Inc. 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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