LD15CHA WAVELENGTH | Alldatasheet

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ORDERING INFORMATION

LD2.5CHA 2.5 A Laser Diode Driver LD5CHA 5 A Laser Diode Driver LD10CHA 10 A Laser Diode Driver LD15CHA 15 A Laser Diode Driver PWRPAK-16A-5V 16 A / 5 V Switching Power Supply WCB325 Power Supply Wiring Kit MEETING LASER REQUIREMENTS The LDxCHA product family has current levels from 2.5 A up to 15 A. These drivers meet laser compliance requirements from 3 V with a single +5 V supply, and up to 28 V with an additional 30 V power supply, supporting applications such as materials processing, industrial laser cutting, and laser diode bars/stacks. This product family supports A & B type laser diodes. WORRY-FREE SETUP The new circuitry in the LDxCHA allows for the laser diode current limit and the laser diode current setpoint to be fine- tuned without output current enabled to the laser. This allows users to set the specific safety and output levels required without risk of overdriving the laser during initial configuration. DESIGNED FOR EASY INTEGRATION The LDxCHA drivers, with their small size and easy mountability, can be attached directly to an optics table or designed into a system. Two trimpots set the current limit and current setpoint, while five screw terminal blocks allow for simple wiring. LASER SAFETY FEATURES Built-in safety features ensure robust designs for real world operating conditions: clipping current limit ensures that the output current will never exceed the setpoint; and slow start circuit ramps the output current. Long-term reliability means better up-time, fewer service calls, and more satisfied customers. FEATURES AND BENEFITS

  • Models: 2.5 A, 5 A, 10 A, and 15 A
  • Single supply operation at +5 VDC for single emitters (3 V maximum to laser)
  • Dual supply operation up to +30 VDC (28 V maximum to laser)
  • Constant Current or Constant Power modes
  • Safety features protect your laser » Adjustable clipping current limit » Slow-start and delay circuitry » Brownout protection » Over-voltage protection
  • Bandwidth 280 kHz to 1 MHz in Constant Current mode (model dependent)
  • RMS Noise Current as low as 7 μA at 100 kHz

CONTENTS

ELECTRICAL SPECIFICATIONS 6 SAFETY INFORMATION 8 OPERATING INSTRUCTIONS 9 ADDITIONAL TECHNICAL INFORMATION 15 TROUBLESHOOTING 21 MECHANICAL SPECIFICATIONS 23 CERTIFICATION AND WARRANTY 24 e PAGE Pb RoHS Compliant © October 2024 Applies to Product Revisions A-B A Laser Type B Laser Type 406-587-4910 www.teamWavelength.com LDxCHA Series Low Noise up to 15 A / 28 V Laser Diode Drivers DATASHEET AND OPERATING GUIDE

lower voltage power supplies are required. Figure 1. LDxCHA Component Locator

5 VDC

To allow modulation, remove JP1. internally in the type B laser. Figure 2. Quick Connect Wiring Diagram, Type A & B Laser Diodes page 10 for a higher compliance voltage wiring diagram. blocks instead of the screw-in terminal blocks on Revision B.

Table 1. Pin Descriptions 1 LDC Connect this pin to the Laser Diode Cathode. 2 LDA Connect this pin to the Laser Diode Anode. This pin is internally connected to V+. 30 V. It is internally connected to the laser diode anode (LDA). 4 GND Used for high current return. This pin is internally connected to pin J5:2. 1 MOD INPUT Use this pin to allow for modulation. Range is -2 V to +5 V. This signal sums with the onboard trimpot. If no modulation, install jumper JP1. 1 Modulation Input Impedance is 2.5 kΩ. 2 GND This pin is the ground reference for modulation. Not to be used for high current return.

3 ENABLE

TTL compatible input that allows remote enabling and disabling of current to the laser diode. To enable current, the voltage at this pin must be <0.3 V. To disable current, the voltage at this pin must be >2 V. The enable circuit uses an internal 10 kΩ pullup resistor. pullup resistor will hold this pin high if it is left floating. 4 LIM MON Monitors the current limit set by the user. Outputs a voltage proportional to the current limit. See Table 2 for model-specific transfer function. Range is 0 to 2.5 V on monitor.

5 LD STATUS

Monitors whether output current is enabled to the laser diode. If output is enabled, there will be +5 V at this pin. If output is disabled, there will be 0 V at this pin. 1 SET MON Monitors the user-defined setpoint. Outputs a voltage proportional to the current setpoint. See Table 2 for model-specific transfer function. Range is 0 to 2.5 V on monitor. 2 I MON Monitors the output current. Outputs a voltage proportional to the current through the laser diode. See Table 2 for model-specific transfer function. Range is 0 to 2.5 V on monitor. 3 P MON Monitors the photodiode output. Outputs a voltage proportional to the current through the photodiode. See Table 2 for model-specific transfer function. Range is 0 to 2.5 V on monitor. 4 GND This pin is the ground reference for the monitors on connector J3. Not to be used for high current return. 1 PDC Connect this pin to the Photodiode Cathode. 2 PDA Connect this pin to the Photodiode Anode. 1 +5V Connect +5 VDC to this pin to power control electronics. Do not exceed 5.5 V at this pin. If single +5 V supply operation is used, install JP2 and only connect the power supply to J1. 1 For more details regarding jumpers, see Table 3 on page 5 and “Install or Remove Jumpers” on page 12.

Table 2. Current Output Monitor, Limit Monitor, Photodiode Current Monitor, and

  • The I LIM MON transfer function is accurate above 5% of maximum current available from the unit.

Table 3. Description of jumper connections and functionality. output current noise. Remove this jumper if external modulation is required. Unit ships with JP1 installed. voltage to the laser diode in this case is 3 V. diode. Maximum voltage to the laser diode in this case is 28 V (using a +30 V supply). Unit ships with JP2 installed. If installed, ties Photodiode Cathode to Laser Diode Anode for Constant Power operation. laser. If the jumper is not removed, damage may occur. Consult the laser manual to determine if this connection is already made internally. Unit ships with JP3 installed.

© 2024 www.teamWavelength.com 6 LDXCHA SERIES LASER DIODE DRIVER ELECTRICAL SPECIFICATIONS PARAMETER SYMBOL VALUE UNIT NOTE ABSOLUTE MAXIMUM RATINGS Control Electronics Voltage (J5:1) +5V 4.8 to 5.5 VDC Undervoltage trip is 4 V. Overvoltage trip is 6 V. Supply Voltage, (J1:3) V+ 5 to 30 VDC Current Limit Range LIM 0.05 to Maximum A Maximum current is model specific Operating Temperature Range TOPR 0 to 40 ºC Storage Temperature Range TSTG -55 to 125 ºC Weight 4 oz 113 grams MODEL PARAMETER LD2.5CHA LD5CHA LD10CHA LD15CHA UNIT NOTE DRIVE CURRENT OUTPUT Max Internal Power Dissipation (No Airflow) 25 25 50 60 W 25°C ambient Max Internal Power Dissipation (With Airflow) 35 35 70 85 W 25°C ambient, 5.5 CFM: 2.5, 5 A models

12 CFM: 10, 15 A models

Max Output Current 2.5 5 10 15 A Compliance Voltage1 3 V max with 5 V power supply input

28 V max with 30 V power supply input V

Short Term Stability, 1 hour < 200 ppm Constant Current Mode RMS Noise Current 7 9 22 35 μA At 100 kHz, with 500 mA output current Noise Current Density 20 35 95 100 nA / √Hz At 500 mA output current Quiescent Current 130 mA Leakage Current 0 μA Temperature Coefficient 100 ppm / ºC PHOTODIODE FEEDBACK Ranges 500 µA, 5 mA, or 100 mA Set by PD RANGE DIP switches Constant Power Mode Output Stability 0.14 0.27 0.03 0.03 % At 200 μA photodiode range, simulated load EXTERNAL MODULATION Modulation Input Damage Threshold VMOD ≤ -3 or VMOD ≥ 8 V Modulation Input Range -2 to +5 V Modulation Input Pin Impedance 2.5 kΩ -3 dB Bandwidth at Half Current, Constant Current Mode 580 600 530 390 kHz Sine wave input -3 dB Bandwidth at Full Current, Constant Current Mode 1080 1000 660 600 kHz Sine wave input Bandwidth at 90% Depth of Modulation at Half Current 1000 430 360 280 kHz Constant Current Mode Square wave input Bandwidth at 90% Depth of Modulation at Full Current 680 580 480 400 kHz Constant Current Mode Square wave input Output Rise Time (Full Current) 0.8 0.8 1.4 1.4 µsec At 10 kHz Output Fall Time (Full Current) 0.76 0.78 1.2 1.2 µsec At 10 kHz 1. Compliance voltage depends on power supply voltage. In high-compliance mode, up to 30 VDC can be input at V+ to achieve up to 28 V (compliance voltage) across the laser diode. A separate 5 VDC power supply is then required for the +5V control electronics pin. A 5 VDC power supply input at V+ results in 3 V compliance voltage.

© 2024 www.teamWavelength.com 7 LDXCHA SERIES LASER DIODE DRIVER ELECTRICAL SPECIFICATIONS (CONTINUED) MODEL PARAMETER LD2.5CHA LD5CHA LD10CHA LD15CHA UNIT NOTE TIMING CHARACTERISTICS Warm Up Time 1 hour Slow Start Delay 2 sec CDRH compliant Slow Start Ramp 20 msec To full scale Disable Fall Time 640 µsec Turn Off Ramp 260 µsec MONITOR ACCURACY Monitor Voltage vs. Expected Output based on transfer function 0.27 0.64 0.52 0.75 % of Full Scale

© 2024 www.teamWavelength.com 8 LDXCHA SERIES LASER DIODE DRIVER SAFETY INFORMATION SAFE OPERATING AREA — DO NOT EXCEED INTERNAL POWER DISSIPATION LIMITS Before attempting to operate the LDxCHA 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 LDxCHA. Operating outside of the SOA will void the warranty. To determine if the LDxCHA 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 19), but we recommend you use the online tools instead. To ensure safe operation of the LDxCHA 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. HEAT SINK TEMPERATURE For single supply, 5 V operation of the LD15CHA, the MULTI-HTSK-HI with recommended airflow is adequate up to 15 A operation. However, when using a second power supply to allow higher voltage operation, the MULTI-HTSK-HI heatsink temperature can exceed 50°C. If operating the LD15CHA under these conditions, a user supplied higher capacity heatsink is required for safe operation. THEORY OF OPERATION The LDxCHA 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 with the onboard trimpot or by an external modulation input that sums with the onboard setpoint. The adjustable current limit is set using an onboard trimpot. As current is driven through the 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 LDxCHA driver includes 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 LDxCHA will hold the output current at or slightly below the limit.
  • Both the current setpoint and the current limit can be set prior to enabling current to the laser diode.
  • Output current switches on after a 2 second delay from the time the enable signal is applied, meeting CDRH requirements.
  • Output slow-start ramps the current to setpoint over 20 msec.
  • The ENABLE pin must be held low in order to have current enabled from the laser driver. If this pin is left floating, an internal pullup circuit will hold the pin high, disabling current output.
  • Over/Under voltage shutdown protection ensures that output current will not be enabled if proper voltage is not supplied.
  • Low noise: down to 7 μA RMS noise current at 100 kHz.

© 2024 www.teamWavelength.com 9 LDXCHA SERIES LASER DIODE DRIVER OPERATING INSTRUCTIONS The LDxCHA requires no external electronic components. These instructions first configure the driver for local control in order to set the drive current limit. Then the driver can be configured to your application. We recommend using a test load until you are familiar with operation of the driver. Refer to page 3 for a test load schematic. NECESSARY EQUIPMENT The following equipment is the minimum necessary to configure the LDxCHA for basic operation:

  • LDxCHA controller
  • Digital voltmeter, 4-½ digit resolution recommended
  • Test load for configuring the driver
  • Laser diode, mount, and optional temperature control system
  • Recommended heat sink » For LD2.5CHA and LD5CHA, use the MULTI-HTSK » For the LD10CHA and LD15CHA, use the MULTI-HTSK-HI
  • Connecting wires
  • Power supply (see below) POWER SUPPLY REQUIREMENTS Linear-regulated or low-noise switching power supplies can be used. We recommend using power supplies with noise specifications suitable for your application. For single-supply operation:
  • 5 VDC power supply rated for 1.1-times the maximum laser diode current, plus 150 – 250 mA for the electronics For dual supply operation to drive a high compliance laser diode, laser diode bar, or laser diode stack:
  • 5 VDC power supply rated for 250 mA for electronics
  • AND a power supply to drive the laser; rated for 1.1-times the maximum laser diode drive current and

2 V greater than the compliance voltage required by the

laser, up to 30 V. PREVENT DAMAGE FROM ELECTROSTATIC DISCHARGE Before proceeding, it is critical that you take precautions to prevent electrostatic discharge (ESD) damage to the driver and your laser. ESD damage can result from improper handling of sensitive electronics, and is easily preventable with simple precautions. For more information on ESD, see Application Note AN-LDTC06: Basics: Electrostatic Discharge (ESD). We recommend that you always observe ESD precautions when handling the LDxCHA driver and your laser diode. Note: The LDxCHA case is isolated from electrical ground. WIRE THE LDxCHA LASER DRIVER There are two possible wiring configurations for the LDxCHA, one for single supply operation, and one for dual supply operation. The figures on the next page serve as a guide for these two configurations. For setup and initial configuration, use a test load (see Figure 4). Each of the terminal blocks on the LDxCHA are screw-in terminal blocks. To attach the necessary wires to the unit, simply loosen the screw, insert the wire into the proper slot, and then tighten the screw to securely fasten the wire to the LDxCHA. For the power supply and laser diode connections (J1), it is recommended to use stranded 18 gauge wire for currents up to 5 A. For current levels greater than 5 A, stranded 14 gauge wire is recommended. The largest size that will fit into the J1 terminal block is 12 gauge. For the remaining terminal blocks (J2 - J5), Wavelength recommends using 24 gauge solid core wire.

If no modulation, install JP1. Figure 5. Type A & B Laser Diode, Single 5 VDC Power Supply, 3 V compliance maximum to the laser diode. All jumpers shown are either installed or uninstalled on the LDxCHA board. If no modulation, install JP1. Figure 6. Type A & B Laser Diode, High Compliance Dual Supply Operation, up to 28 V compliance to the laser diode. All jumpers shown are either installed or uninstalled on the LDxCHA board.

© 2024 www.teamWavelength.com 12 LDXCHA SERIES LASER DIODE DRIVER INSTALL OR REMOVE JUMPERS There are three jumpers located on the circuit board, labeled JP1, JP2, and JP3 (see also Figure 7). They are all two position jumpers, so they are either installed, or uninstalled. The LDxCHA ships with all jumpers installed by the factory. Jumper functionality is described in Table 3 on page 5. DISABLE CURRENT The LDxCHA allows for the user to set the current limit, output current setpoint, and modulation input without current flowing to the laser. In order to set these values with current disabled, ensure that the ENABLE pin (J2:3) is held high (voltage greater than 2 V), or leave this pin floating. Once these values are set to the desired levels, current to the laser can be enabled by holding the ENABLE pin low (voltage less than 0.3 V). CALCULATE THE MONITOR VOLTAGES Output Current Limit: Refer to the datasheet for your laser to determine the maximum forward current, and calculate the current limit monitor voltage (V ILIMMON) using this equation and the transfer function found in Table 2 on page 5: VILIMMON = ILIMIT / Transfer Function Output Current Setpoint: In Constant Current Mode, determine your desired current level and calculate the current setpoint monitor voltage (VISETMON) using the transfer function found in Table 2: VISETMON = ISET / Transfer Function Note: In Constant Power Mode, the output current setpoint is dependent on the photodiode response. Constant Current Mode: If you are using the LDxCHA in Constant Current mode, calculate the monitor voltage for the drive current setpoint. Refer to the datasheet for your laser to determine the nominal forward current, and calculate the I MON voltage using the transfer function found in Table 2: VIMON = ILD / Transfer Function Constant Power Mode: If you are using the LDxCHA in Constant Power mode, calculate the photodiode current monitor voltage, P MON. Refer to the laser diode datasheet to determine the nominal photodiode current at the desired operating point. Choose the correct photodiode range configuration using the DIP switches for this photodiode range. Calculate the P MON voltage using the transfer function found in Table 2: VPMON = IPD / Transfer Function APPLY POWER TO THE LD xCHA In order to monitor these set values, the chosen power supply must be properly wired to the unit and turned on. See Figure 5 and Figure 6 for single and dual supply operation, respectively. SET THE CURRENT LIMIT The current limit on the LDxCHA can be set without enabling current to the laser. In order to monitor the set current limit, connect the positive lead of the digital multimeter to the LIM MON pin (J2:4), and the negative lead to the GND terminal (J2:2). Use the transfer function listed in Table 2 to determine the current limit proportional to the monitor voltage. The onboard LIM trimpot is the only method of setting and adjusting the current limit. This is a 12-turn trimpot that increases with clockwise adjustments, and decreases with counter-clockwise adjustments. Prior to initial adjustment, turn the trimpot 12 full turns counter-clockwise to zero the trimpot. Reference Figure 7 for control locations on the LDxCHA:

  • Disable output current, either by holding the ENABLE pin high, or allowing it to float.
  • Switch on the +5 V power supply to the LDxCHA. (If dual-supply operation is being used, switch on both power supplies.)
  • If the LIM trimpot has not previously been set to zero, do this by turning it at least 12 full turns counter-clockwise.
  • Set the current limit by turning the LIM trimpot clockwise until the voltage displayed on the multimeter matches the value calculated for VILIMMON to the left.
  • Switch off the power supply/supplies. The LDxCHA controllers utilize a clipping current limit, ensuring that the output current will never exceed the limit set by the LIM trimpot. If the current approaches the limit that is set, the controller will clamp the output at or slightly below the limit, until the setpoint is backed down below the limit. Wavelength does not recommend operating in limit.

© 2024 www.teamWavelength.com 13 LDXCHA SERIES LASER DIODE DRIVER ADJUST THE OUTPUT CURRENT SETPOINT – ONBOARD CONTROL The output current setpoint on the LDxCHA can be set without enabling current to the laser. In order to monitor the output current setpoint, connect the positive lead of the digital multimeter to the SET MON pin (J3:1), and the negative lead to the GND terminal (J3:4). Use the transfer function listed in Table 2 to determine the output current from the monitor voltage. The onboard SET trimpot can be used to adjust the current setpoint either alone, or in conjunction with the MOD INPUT pin. If no modulation is necessary, install jumper JP1 to disable modulation input and minimize noise. In this scenario, the SET trimpot is the only method of setting the current setpoint. This is a 12-turn trimpot that increases with clockwise adjustments, and decreases with counter- clockwise adjustments. Prior to initial adjustment, turn the trimpot 12 full turns counter-clockwise to zero the trimpot. Reference Figure 7 for control locations on the LDxCHA:

  • Disable output current, either by holding the ENABLE pin high, or allowing it to float.
  • Switch on the +5 V power supply to the LDxCHA. (If dual-supply operation is being used, switch on both power supplies.)
  • If the SET trimpot has not been previously set to zero, do this by turning at least 12 full turns counter-clockwise.
  • Constant Current Mode: Set the current limit by turning the SET trimpot clockwise until the voltage displayed on the multimeter matches the value calculated for VISETMON on page 12.
  • Constant Power Mode: Wavelength recommends leaving the SET trimpot at zero until current is enabled, and the power output can be monitored by the P MON pin (J3:3), or by an external power meter. See page 14 for further instructions if operating in Constant Power Mode.
  • Switch off the power supply/supplies. ADJUST THE OUTPUT CURRENT SETPOINT – MODULATION INPUT The modulation input to the LDxCHA can be set without enabling current to the laser. To use MOD INPUT (pin J2:1) to adjust the output current, refer to Pin Descriptions on page 4 for specifications. The modulation input signal can either sum with the onboard trimpot value, or provide the output current setpoint alone. If using the modulation input as the single source of setting the output current setpoint, the onboard SET trimpot must be set to zero. If the SET trimpot is not set to zero, the value of the modulation input will sum with the value of the onboard trimpot. JP1 connects the modulation input to ground. In order to utilize modulation input to adjust the output current setpoint in either scenario, JP1 must be removed. Driving the external modulation input with this jumper installed will drive the input signal directly to ground, and may damage the signal source or function generator being used. The modulation input signal can be used whether the driver is operating in Constant Current or Constant Power mode. Refer to Table 2 on page 5 for the transfer function for Constant Current mode. For Constant Power mode, the LDxCHA’s response to modulation input is dependent on the photodiode response. Wavelength recommends waiting to modulate until current is enabled, and the power output can be monitored by the P MON pin (J3:3), or by an external power meter. See page 14 for further instructions if operating in Constant Power Mode. Refer to the External Setpoint Circuit on page 15 for an example analog input circuit. Other circuits, a DAC signal, or function generator may be used. COMBINING THE ONBOARD SETPOINT AND ANALOG INPUT The MOD INPUT voltage signal on J2:1 sums with the onboard trimpot setpoint, provided that JP1 is removed. This configuration allows the driver to be configured so that the laser current or power modulates around a DC setpoint. If the sum of the two signals causes the LDxCHA to attempt to drive the output current past the limit, the output will clip at the limit, providing limit current until the sum of the two signals drops below the set limit. To avoid driving the current to the limit, first set the onboard trimpot to produce the Constant Current level. Then connect the modulation source to the MOD INPUT pin and slowly increase the modulation amplitude. Monitor the output current using the I MON pin, or by measuring the voltage across the test load. Do not monitor the voltage across a laser diode—measurement transients may damage the laser diode.

© 2024 www.teamWavelength.com 14 LDXCHA SERIES LASER DIODE DRIVER USING THE LD STATUS MONITOR PIN Also on the Status Connections header (J2) is the LD STATUS monitor pin. This pin gives a high voltage (+5 V) when current is enabled to the laser, and a low voltage (0 V), when current is disabled. To utilize the LD STATUS pin, connect the positive lead of the voltmeter to the LD STATUS pin (J2:5), and the negative lead to the GND terminal (J2:6). ENABLE LED In addition the LD STATUS pin going high when current is enabled, the LDxCHA has an Enable LED, that will light when output current is enabled. ENABLE CURRENT Once the operating parameters are set to the desired levels, current to the laser can be enabled by holding the ENABLE pin (J2:3) low (voltage less than 0.3 V). MONITOR THE ACTUAL OUTPUT CURRENT Once output is enabled to the laser, the I MON pin (J3:2) can be used to monitor the actual output current that is reaching the laser. To monitor the actual output current, connect the positive lead of the multimeter to the I MON pin, with the negative lead connected to GND (J3:4). Use the corresponding transfer function in Table 2 to relate this monitor voltage to actual current. MONITOR THE PHOTODIODE CURRENT – CONSTANT POWER MODE If the photodiode is connected to the LDxCHA and Constant Power Mode is chosen, the photodiode current can be monitored by connecting the positive lead of a multimeter to the P MON pin (J3:3), with the negative lead on the GND pin (J3:4), and reading the voltage. Refer to Table 2 on page 5 for the transfer function to convert the P MON voltage to PD current. Ensure that the DIP switches are properly oriented for the photodiode range to minimize errors between monitor and actual photodiode currents. Due to the fact that the output current setpoint cannot be accurately set prior to enabling output current in Constant Power Mode, Wavelength recommends starting with the SET trimpot at zero, then enabling output current and slowly increasing the setpoint until the desired power is reached. MONITOR THE MODULATION INPUT – CONSTANT POWER MODE In Constant Power Mode,after enabling current, Wavelength recommends inputting a low depth of modulation signal, and slowly increasing the modulation towards the desired level, while monitoring the results.

requirements, a switching power supply may be acceptable. supply will affect noise, transient, and stability performance. Table 4. Available power supplies. (WCB325) to simplify wiring. should connect to the V+ and GND pins on J1. photodiode current to the LDxCHA is 10% of the full scale. sensitivity to variations in the photodiode current. to whether current is enabled or disabled. Wavelength recommended heatsink. Table 5. Wavelength recommended heatsinks, by model. for Laser Diode Drivers tool. MULTI-HTSK-HI heatsink temperature can exceed 50°C.

© 2024 www.teamWavelength.com 20 LDXCHA SERIES LASER DIODE DRIVER TROUBLESHOOTING PROBLEM POTENTIAL CAUSES SOLUTIONS Driver will not switch on Improperly configured power supply Carefully check the wiring diagram according to page 10. Output will not enable ENABLE pin not held low Refer to the ENABLE pin specifications in Table 1 and make sure this pin is held at a voltage less than 0.3 V. Over- or under-voltage protection has disabled output The LDxCHA drivers have over- and under-voltage protection to protect the laser diode. Ensure that the voltage at the +5V pin (J5:1) is above 4 V, and below 6 V. Laser output power too low in Constant Current mode Laser current setpoint too low Increase the setpoint either by adjusting the SET trimpot clockwise, or by increasing the signal voltage on MOD INPUT (pin J2:1). Laser current limit too low Refer to page 12 for instructions on setting the laser driver current limit. Laser driver is compliance limited Check the laser diode specifications to determine the forward voltage (VF). Make sure that the LDxCHA is not compliance limited. Refer to the Electrical Specifications table on page 6. If the driver is compliance limited, V+ may need to be increased. Verify that the LDxCHA will be operating within the Safe Operating Area if V+ is increased. Laser does not reach desired output in Constant Power mode Photodiode feedback current is out of range for the LDxCHA Refer to the laser diode datasheet to determine the approximate photodiode (PD) current at the desired output power level. If the PD current exceeds the chosen LDxCHA photodiode current range, set the PD Range switch to a higher range; see page 11. Modulation is not working JP1 is not removed The LDxCHA will not allow modulation signals to be passed through to the laser if JP1 is installed. To enable modulation, ensure that JP1 is removed. Cannot zero the trimpots The trimpots that are installed on the LDxCHA are 12-turn trimpots. This means that after 12 full turns counterclockwise, they will be set to zero, even though they will turn continuously. Photodiode feedback is inaccurate Improperly configured PD Range switch If the switches for the PD Range are configured improperly, the LDxCHA will continue to operate, but the values that are returned will be less accurate. Ensure that these switches are oriented as shown in Figure 9 for the desired range. Transfer functions are inaccurate Improperly configured CC/CP Mode switch If the CC/CP Mode switches are improperly configured, this can lead to inaccuracies in the transfer functions. Ensure that these switches are oriented as shown in Figure 8 for the desired operation mode. Dual supplies are not working properly JP2 is not removed If dual supply operation is desired, ensure that JP2 is removed from the board. If JP2 is still installed, this can lead to issues with the power supplies.

© 2024 www.teamWavelength.com 21 LDXCHA SERIES LASER DIODE DRIVER CABLING SPECIFICATIONS WCB308: POWER / LD CABLE (NOT INCLUDED) 2.00” BLACK / RED TWISTED PAIR; 14 AWG WHITE / BLUE TWISTED PAIR; 14 AW G OVERALL LENGTH 24” ± 1” AFTER TWISTING WCB325: LD15CHA SWITCHING POWER SUPPLY CABLES (NOT INCLUDED) Black / White Twisted Pair

14 AWG

Overall length 24” ± 1” Black / Red Twisted Pair Overall length 24” ± 1” Black

24 AWG

Overall length 10” BLACK = AC (Live) WHITE = AC (Neutral) BLACK = GND (J1:4) RED = V+ (J1:3) BLACK = Safety Ground

2 PLS

Figure 24. LDxCHA Driver Mechanical Dimensions

© 2024 www.teamWavelength.com 23 LDXCHA SERIES LASER DIODE DRIVER CERTIFICATION AND WARRANTY CERTIFICATION Wavelength Electronics, Inc. (Wavelength) certifies that this product met its 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 one (1) year 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 other warranty is expressed or implied. 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. 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 Electronics for service and repair to ensure that safety features are maintained. LIFE SUPPORT POLICY This important safety information applies to all Wavelength electrical and electronic products and accessories: 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.

REVISION HISTORY

DOCUMENT NUMBER: LD15CHA-00400 REV. DATE CHANGE A Jan. 2018 Initial Release B Feb. 2021 Updated for screw-in terminal blocks and wiring configurations

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