14
User Manual, Rev 02
Rad-icon 2329 GigE Detector
Teledyne DALSA
Description Input circuitry Trigger In
Inside the detector the connection for the input is as in below drawing
:
FPGA
4pin LEMO
Connector
1
2
3
4
Trigger Input Anode +
Trigger Input Cathode -
Trigger Output Col
Trigger Output Emitter -
TCMT1600
680
10
k
100p
Shield to
mechanical ground
of detector
10
k
+3V3
Inside Detector
Depending of the connection, the trigger input can be active high or active low:
For normal input operation:
“Trigger Input Anode +” is used as driving source and
“Trigger Input Cathode -” is connected to ground.
Then “Trigger in” is active high.
This is the situation which is referred to in this document.
For inversed input operation:
“Trigger Input Anode +” is connected to VCC and
“Trigger Input Cathode -” is used as driving source and then “Trigger in” is active
low.
Voltage range of trigger input:
Active State:
The recommended photodiode forward current is 5mA. Absolute maximum input
voltage is 10.0V. Do not apply an input voltage with reversed polarity. In the detector
there is a series resistor of 680 Ohm. The maximum forward voltage of the
photodiode is 1.35V.
Minimum voltage input:
When 2.4V input voltage is applied then the trigger will be active.
Forward voltage of optocoupler is maximum 1.35V.
The forward current will be (2 - 1.35V)/680 Ohm = 1.5mA.
The optocoupler shall response correctly.
Maximum voltage input:
When 10V input voltage is applied then the trigger will be active.
Typical forward voltage of optocoupler is 1.35V.
The forward current will be (10 - 1.35V)/680 Ohm = 13mA.
The maximum voltage is limited by internal dissipation of internal series resistor
(which is 125mW). In this case the dissipation is 110mW.
By adding external series resistor the external voltage can be increased.
The forward current for the trigger input to the detector may not exceed 13mA.
