Wavelength Electronics WLD3343, Техническое описание и руководство по эксплуатации

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WLD SERIES LASER DIODE DRIVERS
Step 8: Set The Laser Diode Current Limit
The WLD3393 LIM trimpot adjusts the laser diode current
limit from zero to the full 200 mA or 2.2 A, depending on the
laser diode current range selected. For accurate laser diode
current limit configuration, follow these steps sequentially:
A)
Connect a test load across the LDA and LDC terminals
of the WLD3393. See
page 3
for test load information.
Connect a voltmeter across the test load. This voltmeter
will be used to monitor the output current while setting the
current limit. Refer to the datasheet for your laser diode and
find the manufacturer’s recommended current limit (I
LIMIT
),
then calculate the corresponding voltage limit, V
LIMIT
with
Equation (14)
.
V
LIMIT
= I
LIMIT
· R
LOAD
(14)
B) Configure the evaluation board for Constant Current
(CC) operation using the Mode Switch.
C) Turn the SET trimpot at least twelve turns counter-
clockwise (OFF). Adjust the LIM trimpot at least twelve turns
clockwise (ON).
D) Apply power to the WLD3393 and enable the output
current by switching the enable switch to the “ON” position.
See Figure 13 to locate the switch.
E) Adjust the SET trimpot clockwise until the voltmeter
displays V
LIMIT
calculated in Equation (14) . Next, turn the
LIM trimpot counter-clockwise until the displayed voltage
just begins to decrease. Finally, turn the SET trimpot fully
counter-clockwise to zero the output current.
F) Disable the output current by switching the enable switch
to the “OFF” position. Remove power from the WLD3393.
G) Return the Mode Switch to CC or CP, according to your
application.
Step 9: Connect The Laser Diode And Monitor
Photodiode
With power removed from the WLD3393 board, connect
the output (4 wire cable) to your laser diode as indicated
in
Table 8
. Firmly press the output cable into the output
connector.
PIN # WIRE COLOR FUNCTION
1 Red LDA
2 Green PDC
3 White PDA
4 Black LDC
Table 8. Output cable color code.
A Molex 4-pin housing (43645-0400) is the plug used for the
output cable.