3.8 Analog output
LDC340 / Page 22
3.8 Analog output
At the analog output (BNC jack) a voltage directly proportional to the laser current is
available.
The bandwidth of this output is that wide that the laser current is shown exactly in its
actual course of time.
The transmission coefficient of this output is depending on the type of the LDC340.
10 V are corresponding to the maximum output current, so e.g. for a 4A LDC340 10
V correspond to 4A thus the transmission coefficient is 10 V / 4 A = 2.5 V/A.
The shape of the output signal of the LDC340 is limited by the bandwidth and the rise
time of the laser output. This may lead to deviations in the shape of the signal at the
control input compared to that at the control output.
3.9 Setup of polarities and bias voltage
Three hardware presettings can be selected:
3.9.1 Polarity of the Laser diode (LD POL)
The laser diode can either be operated with anode or cathode connected to ground.
If you have chosen the right pins of the output jack you also have to select the right
polarity with the key LD POL in the field SETUP at the front panel.
AG
means laser diode anode is connected to ground.
CG
means laser diode cathode is connected to ground.
A corresponding LED indicates the selection
