VISTEK V1679, User Manual, Page: 12 / 31

VISTEK V1679 single-mode fibre
data transceiver
12 Issue 1
3.3.3 Open Collector Output
Open Collector Outputs can be found quite often in conjunction with GPI Outputs. They provide a flexible way
of interfacing with 3
rd
party equipment without the need of modifications or for additional hardware.
As far as the V1679 GPI Inputs are concerned, the following guidelines apply when connecting to an Open
Collector Output:
•
The Open Collector Output must be capable of sinking at least 5mA (normally specified as I
C
or
CollectorCurrent).
•
The Transistor must withstand at least 12V (minus the voltage drop across the diodes, to be precise) in
the 'off' state (normally specified as V
CE
or Collector-Emitter Voltage).
•
A ground (GND) connection between the remote control unit (Open Collector Output) and the V1679 is
essential.
100R
390R 1K8
GPIOn-
GPIOn+
+5V +12V
1N4148
Input Bias Voltage Selection Jumper
Short to GND Jumper
(open)
On-board power supplies
Rear Connector Side Board Side
Buffer with Open Collector Output
Note:
A com m on GND connection between the rem ote control (Open Collector Output)
and the V1679 m odule (e.g. via dedicated GND PIN on Rear Connector) is
essential.
GND
Figure 6 : Example 3