Wavelength Electronics WLD3343 User manual

WLD3343 GENERAL PURPOSE DRIVER FOR LASER DIODES
www.teamWavelength.com© 2001-2013 WLD3343-00400-O
GENERAL DESCRIPTION:
The WLD3343 is an easy-to-use analog circuit
for space constrained laser diode applications.
The WLD3343 maintains precision laser diode
current (constant current mode) or stable
photodiode current (constant power mode)
regulation using electronics that are compatible
with any laser diode type. Safely supply up to
3 Amps of current to your laser diode from a
single +5 Volt power supply.
Excellent for VCSELs, electro-optical
equipment, and medical/dental systems.
General Purpose Driver for
Laser Diodes & VCSELs
FEATURES:
• Low Cost
• Slow Start Laser Diode Protection
• Drive Up to 3 Amps Output Current
• Constant Current or Power Operation
• Compatible With Any Laser Diode Type
• Small Package Size (1.30” X 1.26” X 0.313”)
• Voltage Controlled Setpoint
• TTL Compatible Shutdown Pin
• Adjustable Current Limit
• Adjustable Current Range
• 2 MHz Constant Current Bandwidth
• Over Temperature Shutdown
• 14-Pin DIP PCB Mount
Figure 1
Top View Pin Layout
and Descriptions
WLD3343
1
2
3
4
5
6
7
14
13
12
11
10
9
8
TOP VIEW
SHD
VSET
IMON
PMON
MODE
LIM
GND
VDD
PD-
PD+
OUTA
RS-
OUTB
RS+
Shutdown Laser Diode Output Current
Setpoint Voltage Input
Laser Diode Current Monitor
Photodiode Current Monitor
Mode Configuration
Laser Diode Current Limit
Power Supply Ground
Power Supply Input
Photodiode Current Sense Resistor Negative Input
Photodiode Current Sense Resistor Positive Input
Output A
Laser Diode Current Sense Resistor Negative Input
Output B
Laser Diode Current Sense Resistor Positive Input
(BOTTOM VIEW)
Up to 500 mA
Add Heatsink &
Thermal Washer for 1 A
Add Fan for 2 A
Pb
RoHS
Com
p
liant
e
Ordering Information
WLD3343
WLD3343HB
WLD3343-3A
WLD3343-2L
WLD3343-3L
WLD3393
WTW002
WHS302
WXC303
WXC304
2.2 A Laser Diode Driver
2.2 A Li+ Battery-compatible Driver
3 A Laser Diode Driver
2.2 A Lower Noise Driver, no CP mode
3 A Lower Noise Driver, no CP mode
Evaluation PCB for WLD3343,
WLD3343-3A, WLD3343-2L,
and WLD3343-3L
Thermal Washer for all WLDs
Heatsink for all WLDs
+5 VDC Fan for all WLDs
+12 VDC Fan for all WLDs
January, 2013

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WLD3343
PAGE 2
WLD3343-00400-O
Figure 2
Quick Connect Diagram
For Type A/B Laser Diodes
Operated in Constant Current Mode
1
2
3
4
5
6
7
14
13
12
11
10
9
8
WLD3343
LASER
DIODE
DRIVER
VDD
RLIM
1TIE GROUND CONNECTIONS DIRECTLY TO PIN 7
RSENSE
ENABLE
DISABLE
IMON
NC
1k:
1
1
1
LD PD LD PD
OR
VDD
D/A
OR OR
Bandgap
Voltage
Reference
See Eq. 7
Constant Current: See Eq. 5
VSET
Adjusting
Limit Current
See Table 2
and Eq. 3
Adjusting Laser
Diode Current Range
See Table 1 or Eq. 1
1
1
RPD IPD =VPD
+
-
VPD
RPD
2k
Part # LM4040
www.national.com
1k
LDMAX
SENSE I
00.1
R
With Eval Board (Rev. Level)
Without Evaluation Board
=
VSET = (Desired ILD) * (2*RSENSE)
LD Range RSENSE
(Rev. C)
2.0 A
200 mA
438 m:
5.01 :
RSENSE
(Rev. A&B)
500 m:
5.1 :
TOP VIEW
An online tool is available
to determine values for external components:
http://www.teamwavelength.com/support/tools.asp.

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WLD3343
PAGE 3
WLD3343-00400-O
Supply Voltage (Voltage on Pin 14)
Output Current (See SOA Chart)
Power Dissipation, TAMBIENT = +25˚C
Operating Temperature, case [2]
Storage Temperature
Weight
ELECTRICAL AND OPERATING
SPECIFICATIONS
Volts DC
Amperes
Watts [1]
˚C
˚C
oz
UNITVALUE
+4.5 to +12.5
2.2 or 3
9
- 40 to + 85 [3]
- 65 to +150
0.6
VDD
ILD
PMAX
TOPR
TSTG
WLD3343
ABSOLUTE MAXIMUM RATINGS
RATING SYMBOL
Amps
Volts
Volts
Volts
Volts
Volts
Volts
Volts
Volts
nsec
nsec
MHz
Seconds
Seconds
mA
ppm
%
%
3
3.0
10.0
200
2.2
200
10.6
10.4
10.1
460
320
2.0
(Depends on PD BW)
0.24
0.01
0
OUTPUT
Current, peak, see SOA chart
Compliance Voltage, Laser Diode Load
Compliance Voltage, Laser Diode Load
Compliance Voltage, Laser Diode Load
Compliance Voltage, Laser Diode Load
Compliance Voltage, Laser Diode Load
Compliance Voltage, Laser Diode Load
Compliance Voltage, Laser Diode Load
Compliance Voltage, Laser Diode Load
Rise Time
Fall Time
Bandwidth
Bandwidth
Slow Start - Delay
Slow Start - Ramp
Leakage Current [4]
CONSTANT CURRENT CONTROL
Short Term Stability, 1 hour
CONSTANT POWER CONTROL
Short Term Stability, 1 hour
Long Term Stability, 24 hours
WLD3343-2A UNITSTEST CONDITIONSPARAMETER
ILD = 100 mA, 5 V
ILD = 1.0 Amp, 5 V
ILD = 2.0 Amps, 5 V
ILD = 3.0 Amps, 5 V
ILD = 100 mA,12 V
ILD = 1.0 Amp,12 V
ILD = 2.0 Amp,12 V
ILD = 3.0 Amp,12 V
ILD= Full Scale
ILD= Full Scale
Constant Current, Sine Wave
Constant Power
TAMBIENT = 25˚C
TAMBIENT = 25˚C
TAMBIENT = 25˚C
Notes:
[1] In the WLD3343 and WLD3343-2L models, internal power dissipation is 1.2 W (without heatsink), 2 W (with
heatsink), and 9 W (with heatsink and fan). In the WLD3343-3A and WLD3343-3L models, internal power dissipation
is 2 W (without heatsink), 3 W (with heatsink), and 10 W (with heatsink and fan).
[2] With Revision D forward of the WLD3343, an internal thermostat has been added to activate Shutdown (SHD)
when the internal temperature exceeds 105˚C. The output will be re-enabled after a 250 to 300 msec slow-start once
the internal temperature drops below 95˚C.
[3] Max ambient operating temperature of the WLD3343-3A and WLD3343-3L is 45°C.
[4] Leakage current specification is based on full current set by RSENSE. See page 9 for information on setting the
current range. Minimum turn on current in the 200 mA range is 350 μA. Minimum turn on current in the 2 A range is
12 mA. This specification applies to Rev. E forward.
Noise: To further reduce noise, the WLD3343-2L and WLD3343-3L models are available. Both
are about 2.5 times lower noise than the WLD3343 and WLD3343-3A, respectively. Constant
Power (CP) mode is not available in these models.
0.01
0.05
WLD3343-3A
3.6
3.5
3.0

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WLD3343
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WLD3343-00400-O
mV
μA
V
dB
V
˚C / W
˚C / W
˚C / W
Seconds
Volts
mA
%
%
%
1
-50 to 150
0 to 2
80
> VDD + 0.5 or < -0.5
30
21.5
3.4
10
5 to 12
10
0.5
3.3
3.5
INPUT
Offset Voltage, initial, Imon
VSET Bias Current (1)
VSET Input Voltage Range
Power Supply Rejection
VSET (Pin 2) Damage Threshold
THERMAL
Heatspreader Temperature Rise
Heatspreader Temperature Rise
Heatspreader Temperature Rise
Pin Solderability
POWER SUPPLY
Voltage, VDD
Current, VDD supply, quiescent
MONITOR ACCURACY
Monitor Voltage versus
Expected Output Current,
based on transfer function
PD Monitor versus Actual
Setpoint versus Actual
Pin 2, TAMBIENT = 25˚C, VCM = 0 V
Full Temperature Range
TAMBIENT = 25˚C
With WHS302 Heat sink, WTW002
Thermal Washer
With WHS302 Heat sink, WTW002
Thermal Washer and 3.5 CFM fan
Solder temp @260˚C
ELECTRICAL AND OPERATING
SPECIFICATIONS - Continued
UNITS
TEST CONDITIONS
PARAMETER WLD3343-2A WLD3343-3A
Notes:
[1] As VSET approaches zero volts, the VSET signal source must sink up to 50 μA. As VSET approaches 2 V, the VSET
signal source must source up to 150 μA.

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WLD3343
PAGE 5
WLD3343-00400-O
Float or connect a zero Volt signal to Pin 1 (SHD) to ENABLE the
output current to the laser diode.
Connect a +3 Volt or greater signal to Pin 1 (SHD) to DISABLE
the output current to the laser diode.
Connect a voltage source between Pin 2 (VSET) and Pin 7
(GND) to control either the laser diode current in constant current
mode or laser diode power in constant power mode. Range
is 0-2.0 volt full scale. Input impedance is 20 kΩ. The offset
voltage is 0.5V when open (applies to Revision D forward). Do
not let the input pin float or damage to the load may result.
Monitor the laser diode forward current using Pin 3 (IMON). The
Laser Diode Current Monitor produces a voltage proportional to
the current flowing through the laser diode.
Monitor the laser diode power using Pin 4 (PMON). The
Photodiode Current Monitor produces a voltage proportional to
the current produced by the laser diode monitor photodiode.
CONSTANT CURRENT OPERATION:
A 1kresistor between Pin 5 (MODE) and Pin 6 (LIM)
configures the WLD3343 to regulate the laser diode’s forward
current.
CONSTANT POWER OPERATION:
A 0.1 μF capacitor between Pin 5 (MODE) and Pin 6 (LIM)
configures the WLD3343 to regulate the laser diode’s output
power.
A resistor connected between Pin 6 (LIM) and Pin 7 (GND) limits
the maximum amount of forward current through the laser diode
Connect the VDD power supply ground connection to Pin 7
(GND).
Connect Pin 8 (RS+) directly to the positive side of the laser
diode current sense resistor. The resistance value of RSENSE
determines the range of forward current through the laser diode.
Connect Pin 9 (OUTB) to the positive side of RSENSE.
Connect Pin 10 (RS-) directly to the negative side of the laser
diode current sense resistor. The resistance value of RSENSE
determines the range of forward current through the laser diode.
PIN DESCRIPTIONS
Shutdown Laser Diode
Output Current
Setpoint Voltage Input or
Modulation Input
Laser Diode Current Monitor
Photodiode Current Monitor
Mode Configuration
Laser Diode Current Limit
Power Supply Ground
Laser Diode Current Sense
Resistor Positive Input
Output B
Laser Diode Current Sense
Resistor Negative Input
SHD
VSET
IMON
PMON
MODE
LIM
GND
RS+
OUTB
RS-
1
2
3
4
5
6
7
8
9
10
Pin Pin # Name Function
Pin Descriptions continued on the next page.

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WLD3343
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TYPE A/B LASER DIODES:
Connect Pin 11 (OUTA) to the cathode connection of the laser
diode for type A/B laser diode operation.
TYPE C LASER DIODES:
Connect Pin 11 (OUTA) to Pin 14 (VDD) for type C laser diode
operation.
TYPE A/B LASER DIODE OPERATION:
CC: Connect Pin 12 (PD+) and Pin 13 (PD-) to Pin 7 (GND).
CP: Connect Pin 12 (PD+) to the anode of the photodiode.
TYPE C LASER DIODE OPERATION:
CC: Connect Pin 12 (PD+) and Pin 13 (PD-) to Pin 7 (GND).
CP: Connect Pin 12 (PD+) to Pin 14 (VDD).
TYPE A/B LASER DIODE OPERATION:
CC: Connect Pin 12 (PD+) and Pin 13 (PD-) to Pin 7 (GND).
CP: Connect Pin 13 (PD-) to Pin 7 (GND).
TYPE C LASER DIODE OPERATION:
CC: Connect Pin 12 (PD+) and Pin 13 (PD-) to Pin 7 (GND).
CP: Connect Pin 13 (PD-) to the cathode of the photodiode.
Power supply input for the WLD3343’s internal control electronics.
Supply range input for this pin is +5 to +12 Volts DC.
LASER DIODE PACKAGE
STYLES
Type A Laser Diode Type B Laser Diode
Common
Cathode
Laser Diode Anode &
Photodiode Cathode Common Isolated Photodiode
Short
Laser Diode Anode
to Photodiode Cathode
OUTA
PD+
PD-
VDD
11
12
13
14
Output A
Photodiode Current Sense
Resistor Positive Input
Photodiode Current Sense
Resistor Negative Input
Power Supply Input
Type C Laser Diode
Common
Anode
Laser Diode Cathode &
Photodiode Anode Common
PIN DESCRIPTIONS
Pin Pin # Name Function

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WLD3343
PAGE 7
WLD3343-00400-O
Caution:
Do not exceed the Safe Operating Area (SOA). Exceeding the SOA voids the warranty.
An online tool is available for calculating Safe Operating Area at:
http://www.teamwavelength.com/support/calculator/soa/soald.php.
To determine if the operating parameters fall within the SOA of the device, the maximum voltage drop across the
controller and the maximum current must be plotted on the SOA curves.
These values are used for the example SOA determination:
Vs = 12 volts
VLoad = 5 volts
ILoad = 1 amp
Follow these steps:
1. Determine the maximum voltage drop across the driver,Vs-VLoad, and mark on the X axis.
Example: 12 volts - 5 volts = 7 volts, Point A)
2. Determine the maximum current, ILoad, through the driver and mark on the Y axis:
(1 amp, Point B)
3. Draw a horizontal line through Point B across the chart. (Line BB)
4. Draw a vertical line from Point A to the maximum current line indicated by Line BB.
5. Mark VSon the X axis. (Point C)
6. Draw the Load Line from where the vertical line from point A intersects Line BB down to Point C.
Refer to the chart shown below and note that the Load Line is in the Unsafe Operating Areas for use with no heatsink
(1) or the heatsink alone (2), but is outside of the Unsafe Operating Area for use with heatsink and Fan (3).
These values are determined from the specifications of the laser diode.
}
Graphs assume:
25°C Ambient
75°C Case
A
BBB
C
SAFE OPERATING AREA & HEATSINK REQUIREMENTS

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WLD3343
PAGE 8
WLD3343-00400-O
Caution:
Do not exceed the Safe Operating Area (SOA). Exceeding the SOA voids the warranty.
An online tool is available for calculating Safe Operating Area at:
http://www.teamwavelength.com/support/calculator/soa/soald.php.
To determine if the operating parameters fall within the SOA of the device, the maximum voltage drop across the
controller and the maximum current must be plotted on the SOA curves.
These values are used for the example SOA determination:
Vs = 9 volts
VLoad = 6 volts
ILoad = 2.5 amps
Follow these steps:
1. Determine the maximum voltage drop across the driver,Vs-VLoad, and mark on the X axis.
Example: 9 volts - 6 volts = 3 volts, Point A)
2. Determine the maximum current, ILoad, through the driver and mark on the Y axis:
(2.5 amps, Point B)
3. Draw a horizontal line through Point B across the chart. (Line BB)
4. Draw a vertical line from Point A to the maximum current line indicated by Line BB.
5. Mark VSon the X axis. (Point C)
6. Draw the Load Line from where the vertical line from point A intersects Line BB down to Point C.
Refer to the chart shown below. Note that the Load Line is in the Safe Operating Area for use with heatsink and fan (3).
It is in the Unsafe Operating Area for use with no heatsink (1) or the heatsink alone (2).
These values are determined from the specifications of the laser diode.
}
Graphs assume:
25°C Ambient
75°C Case
A
BBB
C
SAFE OPERATING AREA & HEATSINK REQUIREMENTS

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WLD3343
PAGE 9
WLD3343-00400-O
1. SELECTING THE LASER DIODE
OUTPUT CURRENT RANGE
The output current range of the WLD3343
depends on the selection of resistor RSENSE
placed between Pin 8 (RS+) and Pin 10 (RS-) as
shown in Figure 3.
Equation 1 calculates RSENSE for a maximum
desired laser diode current, ILDMAX. Refer to
Table 1 to select RSENSE for common laser diode
current ranges.
2. HELPFUL HINTS FOR CHOOSING
RSENSE
• Never use a carbon film resistor for RSENSE.
• Avoid resistors with high parasitic inductance.
• Select a resistor with a low temperature
coefficient (1% ≈100ppm/˚C).
• Place RSENSE as close to Pins 8 (RS+) and
10 (RS-) on the WLD3343 as possible to
avoid parasitic resistance effects from the
PCB layout.
• Use Equation 2 for determining the power
rating of RSENSE.
Note: Wavelength Electronics recommends
a conservative power rating of 2 times normal
maximum for RSENSE. Equation 2 incorporates
this recommendation.
Table 1
Laser Diode Current Sense Resistor RSENSE
vs Maximum Laser Diode Current ILDMAX
Figure 3
Connecting RSENSE
Equation 1
Calculating RSENSE
Constant Power Mode
R
SENSE = 1.25
ILDMAX
OPERATION
Equation 2
Calculating The Power Rating
For RSENSE
RATING = 2 * I2
LDMAX * RSENSE
TYPE A / B Laser Diodes
AB GND
VDD
11 9 1014
WLD3343
LD
RSENSE
87
RS+ RS-
ILD
TYPE C Laser Diodes
AB GND
VDD
11 9 1014
WLD3343
LD
RSENSE
87
RS+ RS-
ILD
Constant Current Mode
R
SENSE = 1.00
ILDMAX
Constant Current
Current
Sense
Resistor,
RSENSE
Maximum
Output
Current
ILDMAX
Constant Power
Current
Sense
Resistor,
RSENSE
50 mA
125 mA
250 mA
500 mA
1.25 Amps
2.2 Amps
3 Amps
25.00 
10.00 
5.00 
2.50 
1.00 
0.57 
0.42 
20.00 
8.00 
4.00 
2.00 
0.80 
0.45 
0.33 
An online tool is available
to determine values for external components:
http://www.teamwavelength.com/support/tools.asp.

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WLD3343
PAGE 10
WLD3343-00400-O
Example 1
Choosing RLIM for a Type A/B Laser Diode
with a 1.5 A Maximum Forward Current in
Constant Current Mode.
Configure the WLD3343 so that ILDMAX is 2.2 A by
selecting RSENSE equal to 0.45 . The Normalized
Maximum Output Current then equals:
A Normalized Output Current of 0.68 (68%)
corresponds to a current limit set resistor RLIM of
405 .
3. CONFIGURING THE LASER DIODE
CURRENT LIMIT
The WLD3343 allows a customized current range for
a specific application. This allows optimized set point
resolution while minimizing output noise. Table 2 (next
page) lists the scaling factors for different current limits
(RLIM).
To select an appropriate resistance value for the limit
resistor (RLIM), the laser diode type and mode of
operation, divide the maximum laser diode current
(determined in Section 1) into the desired maximum
operating current for the laser diode. This result is the
Normalized Maximum Output Current. Choose the
resistance value of the current limit set resistor (RLIM)
shown next to the calculated Normalized Maximum
Output Current.
Use Equation 3 to calculate a precise value
for RLIM.
Setting Current Limits Using Trimpots
Connect a 500 trimpot and a 150 resistor as
shown in Figure 4 to make the maximum current limit
adjustable.
Figure 4
Adjustable Current Limits
Equation 3
Calculating RLIM
==
1.5 Amps
2.2 Amps
0.68
α
ILDLIM RSENSE +1
ILDLIM RSENSE +1
β
RLIM =
β
1-
GND
7
WLD3343
RLIM
6
LIM
CW CCW
W
150 :
500 :
SINGLE TURN
TRIMPOT
OPERATION
Laser Diode Type / Mode 
Type A/B - CC
Type A/B - CP
Type C - CC
Type C - CP
282
350
290
385
2.85
3.35
2.93
3.57
An online tool is available
to determine values for external components:
http://www.teamwavelength.com/support/tools.asp.

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WLD3343
PAGE 11
WLD3343-00400-O
Table 2
Current Limit Set Resistor RLIM vs
Normalized Maximum Output Current
Normalized
Maximum
Output
Current
Type A/B Laser
Diode Constant
Current Limit Set
Resistor RLIM (
 )
Type C Laser Diode
Constant Current
Limit Set Resistor
RLIM (
 )
Type C Laser Diode
Constant Power
Limit Set Resistor
RLIM (  )
Type A/B Laser
Diode Constant
Power Limit Set
Resistor RLIM (
 )
0.00 (0%)
0.04 (4%)
0.08 (8%)
0.12 (12%)
0.16 (16%)
0.20 (20%)
0.24 (24%)
0.28 (28%)
0.32 (32%)
0.36 (36%)
0.40 (40%)
0.44 (44%)
0.48 (48%)
0.52 (52%)
0.56 (56%)
0.60 (60%)
0.64 (64%)
0.68 (68%)
0.72 (72%)
0.76 (76%)
0.80 (80%)
0.84 (84%)
0.88 (88%)
0.92 (92%)
0.96 (96%)
1.00 (100%)
152
162
172
183
194
205
217
230
243
257
272
288
305
322
341
361
382
405
429
455
483
514
547
582
621
664
149
160
171
183
195
208
222
236
251
267
284
301
320
340
361
383
406
432
459
488
519
552
588
627
670
716
150
160
169
179
190
201
213
225
238
251
265
280
296
313
330
349
369
390
412
436
462
490
519
551
586
624
150
160
171
183
195
207
220
234
248
263
279
295
313
331
350
370
392
414
438
463
490
519
550
583
618
656
OPERATION
An online tool is available
to determine values for external components:
http://www.teamwavelength.com/support/tools.asp.

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WLD3343
PAGE 12
WLD3343-00400-O
4. SELECTING THE MONITOR
PHOTODIODE CURRENT RANGE
The monitor photodiode current range
determines the selection of the resistor RPD.
Equation 4 calculates RPD for a maximum
desired photodiode current, IPDMAX. Refer to
Table 3 to select RPD for common photodiode
current ranges.
In constant power mode, the photodiode is used
to control laser output and RPD is connected
across Pin 12 (PD+) and Pin 13 (PD-). In constant
current mode, the photodiode is excluded from
the control circuit and Pin 12 (PD+) and Pin
13 (PD-) are shorted together. The photodiode
current can still be monitored in constant current
mode with RPD. Refer to Figure 5 for photodiode
resistor connections.
Figure 5
Connecting RPD
Equation 4
Calculating RPD
Table 3
Monitor Photodiode Sense Resistor RPD vs
Maximum Photodiode Current IPDMAX
20 μA 50 k
200 μA 5 k
2 mA 500 
20 mA 50 
Maximum Photodiode
Current,
IPDMAX
Monitor Photodiode
Current Sense Resistor,
RPD
PD
R=1
IPDMAX
TYPE A / B TYPE C
GND GND
RPD
RPD
VDD
OR
OR
CONSTANT CURRENT
TYPE A / B TYPE C
PD- PD+
GND GND
V
DD
V
DD
PD- PD+
77
13 13 12 12
14 14
OR
PIN 11
WLD3343 WLD3343
OR
PIN 10
R
PD
R
PD
CONSTANT POWER
OPERATION
5. HELPFUL HINTS FOR
CHOOSING RPD
• Never use a carbon film resistor for RPD.
• Select a resistor with a low temperature
coefficient (ppm/˚C).
• Place RPD as close to Pins 12 (PD+) and 13
(PD-) on the WLD3343 as possible to avoid
parasitic resistance effects from the PCB
layout when in constant power mode.
An online tool is available
to determine values for external components:
http://www.teamwavelength.com/support/tools.asp.

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WLD3343
PAGE 13
WLD3343-00400-O
Figure 6
Disabling Output Current
14 1
VDD WLD3343
ENABLE
DISABLE
SHUTDOWN
SWITCH
SHD
14 1
VDD WLD3343 SHD
TTL INPUT
ENABLE
DISABLE
OR
6. DISABLING OUTPUT CURRENT
The output current can be enabled and disabled
as shown in Figure 6 using a SPST (Single-Pole
Single-Throw) switch or a TTL signal.
NOTE:
Do not insert or remove the laser diode from the
WLD3343 circuit with power applied to the unit.
OPERATION

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WLD3343
PAGE 14
WLD3343-00400-O
1
2
3
4
5
6
7
14
13
12
11
10
9
8
WLD3343
LASER
DIODE
DRIVER
VDD
R
PD
R
LIM
1TIE GROUND CONNECTIONS DIRECTLY TO PIN 7
R
SENSE
ENABLE
DISABLE
IMON
PMON
0.1 PF
1
1
1
LD PD LD PD
OR
VDD
D/A
OR OR
Bandgap
Voltage
Reference
See Eq. 7
See Eq. 9
Constant Power: See Eq. 6
V
SET
Adjusting
Limit Current
See Table 2
and Eq. 3
Adjusting Laser Diode
Current Range
See Table 1 or Eq. 1
Adjusting Photodiode
Current Range
See Table 3 or Eq. 4
1
2k
www.national.com
Part #LM4040
1k
PDMAX
PD I
1
R
With Evaluation Board
Without Evaluation Board
=
V
SET
= (Desired I
PD
) * (2*R
PD
)
PD Range R
PD
2.0 mA
200 PA
499 :
4.99 k:
LDMAX
SENSE I
25.1
R
With Eval Board (Rev. Level)
Without Evaluation Board
=
LD Range R
SENSE
(Rev. C)
2.0 A
200 mA
438 m:
5.01 :
R
SENSE
(Rev. A&B)
500 m:
5.1 :
1
2
3
4
5
6
7
14
13
12
11
10
9
8
WLD3343
LASER
DIODE
DRIVER
VDD
R
LIM
1
TIE GROUND CONNECTIONS DIRECTLY TO PIN 7
R
SENSE
ENABLE
DISABLE
IMON
NC
1k:
1
1
1
LD PD LD PD
OR
VDD
D/A
OR OR
Bandgap
Voltage
Reference
See Eq. 7
Constant Current: See Eq. 5
V
SET
Adjusting
Limit Current
See Table 2
and Eq. 3
Adjusting Laser
Diode Current Range
See Table 1 or Eq. 1
1
1
R
PD
I
PD
=V
PD
+
-
V
PD
R
PD
2k
Part # LM4040
www.national.com
1k
LDMAX
SENSE
I
00.1
R
With Eval Board (Rev. Level)
Without Evaluation Board
=
V
SET
= (Desired I
LD
) * (2*R
SENSE
)
LD Range R
SENSE
(Rev. C)
2.0 A
200 mA
438 m:
5.01 :
R
SENSE
(Rev. A&B)
500 m:
5.1 :
Free Design Calculator: http://www.teamwavelength.com/support/calculator/wld/default.php
7. OPERATING a Type A/B Laser Diode
Figure 7
A/B Laser Diode Constant Current Operation
Figure 8
A/B Laser Diode Constant Power Operation
Free Design Calculator: http://www.teamwavelength.com/support/calculator/wld/default.php
TOP VIEW
TOP VIEW

www.teamWavelength.com© 2001-2013
WLD3343
PAGE 15
WLD3343-00400-O
1
2
3
4
5
6
7
14
13
12
11
10
9
8
WLD3343
LASER
DIODE
DRIVER
RPD
RLIM
1TIE GROUND CONNECTIONS DIRECTLY TO PIN 7
RSENSE
ENABLE
DISABLE
IMON
PMON
0.1 PF
1
VDD
D/A
OR OR
Bandgap
Voltage
Reference
See Eq. 7
See Eq. 9
Constant Power: See Eq. 6
VSET
Adjusting
Limit Current
See Table 2
and Eq. 3
Adjusting Laser Diode
Current Range
See Table 1 or Eq. 1
Adjusting Photodiode
Current Range
See Table 3 or Eq. 4
1
VDD
1
LD PD LD PD
OR
2k
Part #LM4040
www.national.com
1k
PDMAX
PD I
1
R
With Evaluation Board
Without Evaluation Board
=
V
SET
= (Desired I
PD
) * (2*R
PD
)
PD Range RPD
2.0 mA
200 PA
499 :
4.99 k:
LDMAX
SENSE I
25.1
R
With Eval Board (Rev. Level)
Without Evaluation Board
=
LD Range RSENSE
(Rev. C)
2.0 A
200 mA
438 m:
5.01 :
RSENSE
(Rev. A&B)
500 m:
5.1 :
1
2
3
4
5
6
7
14
13
12
11
10
9
8
WLD3343
LASER
DIODE
DRIVER
VDD
RLIM
1TIE GROUND CONNECTIONS DIRECTLY TO PIN 7
RSENSE
ENABLE
DISABLE
IMON
NC
1k:
1
1
1
LD PD LD PD
OR
VDD
D/A
OR OR
Bandgap
Voltage
Reference
See Eq. 7
Constant Current: See Eq. 5
VSET
Adjusting
Limit Current
See Table 2
and Eq. 3
Adjusting Laser
Diode Current Range
See Table 1 or Eq. 1
1
RPD IPD =VPD
+
-
VPD
RPD
VDD
2k
Part #LM4040
www.national.com
1k
LDMAX
SENSE I
00.1
R
With Eval Board (Rev. Level)
Without Evaluation Board
=
V
SET
= (Desired I
LD
) * (2*R
SENSE
)
LD Range RSENSE
(Rev. C)
2.0 A
200 mA
438 m:
5.01 :
RSENSE
(Rev. A&B)
500 m:
5.1 :
8. OPERATING a Type C Laser Diode
Figure 9
Type C Laser Diode Constant Current Operation
Figure 10
Type C Laser Diode Constant Power Operation
TOP VIEW
TOP VIEW
Free Design Calculator: http://www.teamwavelength.com/support/calculator/wld/default.php
Free Design Calculator: http://www.teamwavelength.com/support/calculator/wld/default.php

www.teamWavelength.com© 2001-2013
WLD3343
PAGE 16
WLD3343-00400-O
OPERATION
9. CONTROLLING THE LASER
DIODE FORWARD CURRENT IN
CONSTANT CURRENT MODE
Equation 5 calculates the laser diode forward
current produced by applying a voltage at Pin 2
(VSET) in constant current mode.
10. CONTROLLING THE MONITOR
PHOTODIODE CURRENT IN
CONSTANT POWER MODE
Equation 6 calculates the monitor photodiode
current produced by applying a voltage at Pin 2
(VSET)in constant power mode.
11.TYPICAL OPERATION OF THE
VOLTAGE CONTROL INPUT
Figure 11 illustrates a typical configuration of the
WLD3343 voltage input.
CAUTION: CONNECTING VOLTAGES
OUTSIDE THE RANGE OF VDD TO GND TO
THE VOLTAGE SETPOINT INPUT ON PIN
2 (VSET) CAN RESULT IN DAMAGE TO THE
WLD3343 OR YOUR LASER DIODE.
12. MEASURING LASER DIODE
FORWARD CURRENT USING THE
CURRENT MONITOR OUTPUT
Equation 7 provides a transfer function for
converting the voltage output of Pin 3 (IMON) to
the amount of forward current flowing through the
laser diode.
13.MEASURING MONITOR
PHOTODIODE CURRENT IN
CONSTANT CURRENT MODE
Equation 8 provides a transfer function for
converting the voltage across RPD to the
amount of current flowing through the monitor
photodiode in constant current mode.
14. MEASURING MONITOR
PHOTODIODE CURRENT IN
CONSTANT POWER MODE
USING THE POWER MONITOR
OUTPUT
Equation 9 provides a transfer function for
converting the voltage output of Pin 4 (PMON)
to the amount of current flowing through the
monitor photodiode in constant power mode.
Figure 11
Configuring The Voltage Input
Equation 5
Constant Current Control
Equation 8
Monitor Photodiode Current Measurement in
Constant Current Mode
Equation 7
Laser Diode Forward Current Measurement
Equation 6
Constant Power Control
Equation 9
Monitor Photodiode Current Measurement in
Constant Power Mode
ILD
VPIN2
2*RSENSE
[AMPS]
=
IPD
VPIN2
2*R
[AMPS]
=
PD
IPD
VR
[AMPS]
=
PD
RPD
IPD
VPIN4
[AMPS]
=
RPD
2*
GND
7
WLD3343
2
VSET
2 k:
1 k:
DC BIAS
TRIMPOT
2.5 V
Bandgap
Voltage
Reference
VPIN2
VDD
OR OR
+
ILD
VPIN3
2*R
[AMPS]
=
SENSE

www.teamWavelength.com© 2001-2013
WLD3343
PAGE 17
WLD3343-00400-O
MECHANICAL SPECIFICATIONS
PIN DIAMETER: 0.020”
PIN LENGTH: 0.126”
PIN MATERIAL: Nickel Plated Steel
HEAT SPREADER: Nickel Plated Aluminum
PLASTIC COVER: LCP Plastic
ISOLATION: 1200 VDC any pin to case
THERMAL WASHER: WTW002
HEATSINK: WHS320
FANS: WXC303 (+5VDC)
or WXC304 (+12VDC)
with heatsink and fan
with heatsink
0.87
[22.1]
0.600
[15.24]
Sym.
0.100
[2.54]
WLD3343
BOTTOM VIEW
0.01
[0.3] 0.31 [7.9]
0.48
[12.2]
0.40 [10.2]
0.07 [1.8]
1.27
[32.3]
0.900
[22.86]
0.600
[15.24]
0.100
[2.54]
1.30
[33 0]
0.20
[5.1]
1.26
[32.0]
0.33
1.28
[32.5]
0.945 [24.00]
0.945
[24.00]
2 PLS
4-40 UNC
0.125 [3.18] Thru
0.25 [6.4] DIA KEEPOUT
4 Required
0.038 [0.97] Dia Thru Hole
0.060 [1.52] Dia Pad
14 Required
0.023 [0.58] 0.023 [0.58]
0.900 [22.86]
0.945 [24.00] SQ.
0.175 [4.45]
0.100 [2.54]
PCB FOOTPRINT
Screw: 4-40 PHPH
(x.75” w/o FAN)(x1” w/ FAN)
30 mm FAN
WXC303 (+5VDC) or
WXC304 (+12VDC)
WHS302 Heatsink
WTW002
Thermal Washer
WLD3343
WLD3343 ASSEMBLED WITH
HEATSINK & FAN
↓Air Flow ↓
Heat Spreader
4-40 UNC
Weights
WLD3343 0.6 oz
WHS302 Heatsink 0.5 oz
WXC303/4 Fan 0.3 oz
Air Flow
Dimensions are inches [mm].
All tolerances are 5%.
* Actual fan wire configuration
may be different than shown.
Fan can be rotated on the WLD
so the location of the wires
matches your PCB layout.
The WLD3343 can be directly soldered
to a PCB or installed in a socket soldered
to the PCB. Two 7-pin SIP sockets are
required. Wavelength recommends
Aries Electronics, PN 25-0513-10.

www.teamWavelength.com© 2001-2013
WLD3343
PAGE 18
WLD3343-00400-O
NOTICE:
The information contained in this document is
subject to change without notice. Wavelength
will not be liable for errors contained herein
or for incidental or consequential damages in
connection with the furnishing, performance, or
use of this material. No part of this document may
be translated to another language without the
prior written consent of Wavelength.
SAFETY:
There are no user serviceable parts inside this
product. Return the product to Wavelength
for service and repair to ensure that safety fea-
tures are maintained.
LIFE SUPPORT POLICY:
As a general policy, Wavelength Electronics, Inc. does
not recommend the use of any of its products in life
support applications where the failure or malfunction
of the Wavelength product can be reasonably
expected to cause failure of the life support device
or to significantly affect its safety or effectiveness.
Wavelength will not knowingly sell its products for
use in such applications unless it receives written
assurances satisfactory to Wavelength that the
risks of injury or damage have been minimized, the
customer assumes all such risks, and there is no
product liability for Wavelength. Examples of devices
considered to be life support devices are neonatal
oxygen analyzers, nerve stimulators (for any use),
auto transfusion devices, blood pumps, defibrillators,
arrhythmia detectors and alarms, pacemakers,
hemodialysis systems, peritoneal dialysis systems,
ventilators of all types, and infusion pumps as well
as other devices designated as “critical” by the FDA.
The above are representative examples only and
are not intended to be conclusive or exclusive of any
other life support device.
CERTIFICATION AND WARRANTY
CERTIFICATION:
Wavelength Electronics (Wavelength) certifies that
this product met it’s published specifications at the
time of shipment. Wavelength further certifies that its
calibration measurements are traceable to the United
States National Institute of Standards and Technology,
to the extent allowed by that organization’s calibration
facilities, and to the calibration facilities of other
International Standards Organization members.
WARRANTY:
This Wavelength product is warranted against
defects in materials and workmanship for a period of
90 days from date of shipment. During the warranty
period, Wavelength will, at its option, either repair or
replace products which prove to be defective.
WARRANTY SERVICE:
For warranty service or repair, this product must
be returned to the factory. An RMA is required
for products returned to Wavelength for warranty
service. The Buyer shall prepay shipping charges
to Wavelength and Wavelength shall pay shipping
charges to return the product to the Buyer upon
determination of defective materials or workmanship.
However, the Buyer shall pay all shipping charges,
duties, and taxes for products returned to Wavelength
from another country.
LIMITATIONS OF WARRANTY:
The warranty shall not apply to defects resulting from
improper use or misuse of the product or operation
outside published specifications.
No otherwarranty isexpressed orimplied. Wavelength
specifically disclaims the implied warranties of
merchantability and fitness for a particular purpose.
EXCLUSIVE REMEDIES:
The remedies provided herein are the Buyer’s sole
and exclusive remedies. Wavelength shall not be
liable for any direct, indirect, special, incidental, or
consequential damages, whether based on contract,
tort, or any other legal theory.
REVERSE ENGINEERING PROHIBITED:
Buyer, End-User, or Third-Party Reseller are
expressly prohibited from reverse engineering,
decompiling, or disassembling this product.
WAVELENGTH ELECTRONICS, INC.
51 Evergreen Drive
Bozeman, Montana, 59715
phone: [phone] Sales/Tech Support
fax: [phone]
e-mail: [email protected]
web: www.teamwavelength.com
REVISION HISTORY
REVISION
REV. I
REV. J
REV. K
REV. L
REV. M
REV. N
REV. O
DATE
31-Aug-09
21-May-10
8-Oct-10
3-Jun-11
16-Dec-11
10-Feb-12
25-Jan-13
NOTES
Updated mechanical
specification and links
WLD Rev. E released
-- lower noise, no leakage
current, several models
Added VSET input limits
Updated mechanical
specifications
Updated mechanical
specifications
Updated VSET
specifications and pin
description
Added socket
recommendation