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8

WLD SERIES LASER DIODE DRIVERS

SAFETY INFORMATION

SAFE OPERATING AREA — DO NOT EXCEED 
INTERNAL POWER DISSIPATION LIMITS

Before attempting to operate the WLD3343 driver, it is 

imperative that you first determine that the unit will operate 

within the 

Safe Operating Area

 (SOA). Operating outside 

of the SOA may damage the laser and the WLD3343. 

Operating outside of the SOA will void the warranty.

To determine if the WLD3343 driver will be operating in a 

safe range, follow the instructions for calculating the Safe 

Operating Area online with your system’s voltages and 

current requirements: 

www.teamwavelength.com/support/design-tools/soa-ld-calculator/

SOA charts are included in this datasheet for quick reference 

(

page 23

), but we recommend you use the online tools 

instead.

!

To  ensure  safe  operation  of  the  WLD3343 

driver, it is imperative that you  determine if 

the unit is going to be operating within the 

internal  heat  dissipation  Safe  Operating 

Area (SOA).

If you have any questions about the Safe Operating Area 

calculator, call the factory for free and prompt technical 

assistance.

THERMAL MANAGEMENT KITS

The WLD Series of laser diode drivers have many thermal 

management accessories. They include thermal washers, 

heatsinks, and fans. These products are available either as 

individual accessories, or bundled together in kits. The use 

of these thermal management accessories helps ensure 

that the WLD will remain in the SOA during operation.

THEORY OF OPERATION

The WLD Series drivers are voltage controlled current 

sources: they deliver the current commanded by the 

setpoint. The control system continually monitors the actual 

output current, compares it to the setpoint, and adjusts the 

current if there is a difference between the two signals.

It may be useful to remember that you do not directly set 

the drive current setpoint; instead, you adjust a voltage 

signal that represents the output current. The voltage and 

output current are related by a transfer function that varies 

by driver model number and maximum current.

The setpoint voltage is adjusted at Pin 2 (V

SET

). In standalone 

operation, this is the only way to vary the setpoint. If using 

the evaluation board, there are trimpots that can also adjust 

the setpoint.

The adjustable current limit is set by choosing the resistor 

R

LIM

 in standalone operation, or with a trimpot if using the 

evaluation board.

As current is driven through the laser diode load, there is 

a voltage drop across the load because of its impedance. 

As the current increases, the voltage drop may increase to 

the point that it reaches the Compliance Voltage limit of the 

current source. Once that occurs, the current source is no 

longer able to increase the current driven to the load even if 

you increase the setpoint. 

The WLD drivers include features that help protect your 

laser and make the driver more versatile in a wide array of 

applications:

•  The user-adjustable clipping current limit protects the 

laser from over-current situations by never allowing 

the output current to exceed the user-set limit. If the 

setpoint is greater than the limit, the WLD will hold the 

output current at the limit.

•  Operate in Constant Current or Constant Power mode. 

Constant Current keeps the current through the laser 

diode constant, while Constant Power keeps the current 

through the monitor photodiode constant (proportional 

to output power).

•  Output current switches on after a 250 ms overall delay 

from the time the enable signal is applied.

• 

The  ENABLE  pin  must  be  held  low  or  left  floating  in 

order to have current enabled from the laser driver. To 

disable output, connect greater than 3 V to Pin 1.

•  Low leakage current, excellent for VCSELs.

Summary of Contents for WLD3343

Page 1: ...f the WLD3343 laser diode driver Onboard switches connectors and trimpots make the configuration and operation simple Input and output cables are also included with the WLD3393 The WLD3343 is excellen...

Page 2: ...or 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...

Page 3: ...D VS 2 5 1 ILIM and the power rating of the resistor is found by PRLOAD I2 LIM RLOAD 2 For example if VS is 12 V and the current limit is 2 A then RLOAD needs to be 4 75 with a power rating of 19 W Th...

Page 4: ...apacitor between this pin and Pin 6 LIM 6 LIM Laser Diode Current Limit A resistor connected between this pin and Pin 7 GND limits the maximum amount of forward current through the laser diode See pag...

Page 5: ...0 A or 2 mA POWER SELECT Separate or tied power supplies Configures the WLD3393 to either use separate VS and VDD supplies or to tie the VS and VDD connections for single supply operation VSET SOURCE...

Page 6: ...cale Fall Time 320 ns ILD Full Scale Bandwidth 2 2 MHz CC Sine Wave 2A Slow Start Delay Time 0 24 sec Slow Start Ramp Time 0 01 sec Leakage Current 3 0 mA CONSTANT CURRENT CONTROL Short Term Stability...

Page 7: ...Heatsink No Airflow 2 2 3 W TAMBIENT 25 C Max Internal Power Dissipation Heatsink Fan 9 9 10 W TAMBIENT 25 C Heatspreader Temperature Rise TAMBIENT 25 C 30 C W No heatsink washer fan 21 5 C W With WHS...

Page 8: ...erence between the two signals It may be useful to remember that you do not directly set the drive current setpoint instead you adjust a voltage signal that represents the output current The voltage a...

Page 9: ...1 times the maximum laser diode current plus 150 250 mA for the electronics The HB offers low voltage operation for use with a Lithium ion battery or other low voltage power supplies PREVENT DAMAGE F...

Page 10: ...NSE CC 1 00 4 ILDMAX ILDMAX CONSTANT POWER RSENSE CONSTANT CURRENT RSENSE 50 mA 25 00 20 00 125 mA 10 00 8 00 250 mA 5 00 4 00 500 mA 2 50 2 00 1 25 A 1 00 0 80 2 2 A 0 57 0 45 WLD3343 3A WLD3343 3L O...

Page 11: ...y calculate the value of RLIM use Equation 7 and Table 4 for the values of and RLIM ILDLIM RSENSE 1 7 1 ILDLIM RSENSE 1 LASER DIODE TYPE MODE Type A B CC 282 2 85 Type A B CP 350 3 35 Type C CC 290 2...

Page 12: ...connections TYPE A B TYPE C GND GND RPD RPD VDD OR OR CONSTANT CURRENT TYPE A B TYPE C PD PD GND GND VDD VDD PD PD 7 7 13 13 12 12 14 14 OR PIN 11 WLD3343 WLD3343 OR PIN 10 RPD RPD CONSTANT POWER Figu...

Page 13: ...ured for Constant Current operation Constant Power 1 2 3 4 5 6 7 14 13 12 11 10 9 8 WLD3343 LASER DIODE DRIVER VDD RPD RLIM 1 TIE GROUND CONNECTIONS DIRECTLY TO PIN 7 RSENSE ENABLE DISABLE IMON PMON 0...

Page 14: ...B 500 m 5 1 Figure 10 Type C laser configured for Constant Current operation Constant Power 1 2 3 4 5 6 7 14 13 12 11 10 9 8 WLD3343 LASER DIODE DRIVER RPD RLIM 1 TIE GROUND CONNECTIONS DIRECTLY TO P...

Page 15: ...IPD VPIN2 10 2 RPD MONITORING THE LASER DIODE CURRENT PIN 3 Pin 3 IMON produces a voltage proportional to the current flowing through the laser diode Equation 11 provides a transfer function for conv...

Page 16: ...ch Output Current Enable Disable Switch Fan Power Input Cable Connector Output Cable Connector Optional Supply Input NOTE LINE UP ARROW WITH LASER TYPE INDICATED ON MAIN BOARD Figure 13 WLD3393 Top Vi...

Page 17: ...lable options are the 200 mA or the 2 A position PD RANGE Jumper Set the PD RANGE jumper on the bottom of the WLD3393 to either the 200 A or the 2 mA range depending on the specifications of your phot...

Page 18: ...r to the WHS302 WTW002 WXC303 and or the WXC304 datasheets for assembly instructions Fan Connections Connect the fan leads to the and fan power positions on the terminal block and secure with a small...

Page 19: ...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 p...

Page 20: ...nt controls the output of the WLD3343 The setpoint voltage can be adjusted using the onboard SET trimpot applying an external setpoint voltage or by summing the two signals The VSET SOURCE jumper must...

Page 21: ...the onboard toggle switch The output is enabled when the green ON LED indicator is lit see Figure 13 You can also remotely enable the WLD3343 by connecting a control signal to a via See Figure 19 Thi...

Page 22: ...A range BANDWIDTH OPTIMIZATION WITH THE WLD3393 EVALUATION BOARD To improve bandwidth shorten the cables Expect 1 8 MHz at 200 mA and 850 kHz at 2 A sine wave 3 dB point with factory length cables PO...

Page 23: ...sects the VDROP line On the X axis mark value of VS Extend a diagonal line from VS to the intersection of the VDROP and IMAX lines this is the Load Line If the Load Line crosses the Safe Operating Are...

Page 24: ...C8 1 0 F R27 51 1 C4 4 7 F D5 B0540W VA MODE VDD PDM VA VA R4 332 VA VA R17 499 R16 4 99K R23 1 00M R24 1 00M R22 1 00M R14 1 00M R7 1 00K R9 1 00K R8 1 00K R10 1 00K R6 1 00K 2 3 1 8 4 U4A AD8032 5...

Page 25: ...thin the Safe Operating Area if VDD is increased Laser does not reach desired output in Constant Power mode Photodiode feedback current is out of range for the WLD Refer to the laser diode datasheet t...

Page 26: ...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 WEIGHTS WLD3343 0 6 oz WHS302 Heatsink 0 5 oz WXC 303 4 0...

Page 27: ...lex 43645 00400 33 5 1 32 23 6 0 93 14 2 0 56 25 4 1 00 1 875 47 63 4 8 0 19 2 25 57 1 2 38 60 5 1 875 47 63 2 25 57 1 1 3 0 05 4 4 0 17 2 48 62 9 4 78 0 188 4 8 0 19 The WLD3343 connects to the evalu...

Page 28: ...this product 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...

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