3.1 Connecting components
LDC2xx / page 13
The laser diode is always sourced with re spect to ground. Compared to a floating
driver stage, this operation mode has the advantages of higher security for the laser
diode and better stability of the laser current.
If the photodiode shall be operat ed with bias voltage a battery can be connected in
series to the photodiode.
With polarity AG connect the positive terminal of the battery to the cathode of the
photodiode and the negative terminal of the battery to pin 2.
With polarity CG connect the negative terminal of the battery to the anode of the
photodiode and the positive terminal of the battery to pin 4.
+
-
pin 2
+
-
pin 4
AG with Bias
CG with Bias
Figure 6
Connecting laser diode and photodiode
Attention
A wrong polarity of the battery may destroy the photodiode due to a
forward current flowing through it!