Wavelength Electronics WLD33ND, Техническое описание и руководство по эксплуатации

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WLD SERIES LASER DIODE DRIVERS
RECOMMENDED TEST LOAD
For initial setup and configuration, we recommend using a
test load with the WLD. The test load takes the place of the
laser diode in the corresponding wiring diagram.
• For standalone operation:
»
Type A/B wiring diagrams on page 13 .
»
Type C wiring diagrams on page 14 .
• For operation with the WLD33ND-EV evaluation board:
»
Connect the test load across the LDA and LDC
terminals.
When using the test load, the actual drive current can be
determined by measuring the voltage drop across the
resistor. Do not place an ammeter in series with the load
circuit.
Wavelength recommends using a power resistor. The
resistance value is calculated using
R
LOAD
=
V
S
- 2.5
(1)
I
LIM
and the power rating of the resistor is found by
P
RLOAD
= I
2
LIM
· R
LOAD
(2)
For example, if V
S
is 12 V, and the current limit is 2 A, then
R
LOAD
needs to be 4.75 Ω with a power rating of 19 W.
The WLD33ND Series of laser diode drivers are able to drive lasers with any pinout of laser diode and photodiode. Figure 3
illustrates these laser types. For detailed instructions on using the different laser types refer to the Operating Instructions
— General along with the Operating Instructions — Standalone and Operating Instructions — With Evaluation Board
depending on the desired operation.
Type A Laser Diode Type B Laser Diode Type C Laser Diode
Common
Cathode
Laser Diode Anode &
Photodiode Cathode Common
Isolated Photodiode
Short the
Laser Diode Anode
to Photodiode Cathode
Common
Anode
Laser Diode Cathode &
Photodiode Anode Common
Figure 3. Laser type diagrams. The WLD33ND can operate Type A, B, and C laser diodes.