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3.1 Connecting components
LDC2xx / page 12
Pin 1 and pin 5 must be connected externa lly by a wire (total resistance <430
Ω
).
When opening this connection, the LDC2xx swit ches automatically into LASER OFF
mode.
A LED can be connected in parallel to a resistor of <470
Ω
between pin 1 and pin 5.
This LED lights up when the laser current is switched on (LASER ON).
With the LDC2xxB the LED ERR (L6) lights up if the interlock is open.
3.1.3 Connecting the laser diode and photodiode
Connect laser diode and photodiode according to Figure 5 to the LDC2xx.
The ground connection of the laser diode (pin 3) may be connected to the anode of
the photodiode (pin 4) or to the cathode of the photodiode (pin 2). This connection
should be as close as possible to the laser diode to avoid measuring errors.
If the polarity selected with the switch "LD POL" (R6) and the connection of the laser
diode do not agree, no current is flowing through the laser diode.
LD POL:
AG
AG
CG
CG
Figure 5
Connecting laser diode and photodiode