3.3 Display
LDC340 / Page 19
We recommend to use “twisted pair“ wiring for the monitor diode current, bias voltage
and laser voltage measurement respectively in a common shield. The shield must be
connected to ground (pin 3).
3.2.5 Temperature window protection input (WIN IN)
If you use the LDC340 together with a temperature controller you can use the
temperature window input (WIN IN) to switch off the laser current, if the temperature
leaves a predefined window. Please connect the according output of a TED350 by
means of a BNC cable to this BNC input to get the advantages of a temperature
protection.
Attention
WIN IN input voltage must not exceed TTL level (5V max.!)
3.3 Display
The display is a 4 ½ digit LED-display and shows the value selected in the field
marked “Display selection“ continuously. Additionally 10 single LED's indicate the unit
of the displayed value (A, mA, mW and V) and possible errors.
If the value to be shown is a set value (i. e. the laser current with the output switched
off) this is indicated with the LED “PRESET“ lighting up.
If the value to be shown is a measurement value (i. e. the laser current with the
output switched on) the LED “PRESET“ is off.
Possible error messages:
LIMIT
lights up if a limit value is reached
LD OPEN
lights up if the wiring to the laser is interrupted while the laser is
switched on or if the compliance voltage is insufficient (e.g. operating
two lasers in series requiring more than the capable compliance volt-
age of the LDC340)
