P Series Laser Diode Drivers GENERAL DESCRIPTION The P Series Laser Diode Drivers combine the high performance you expect from a Wavelength component with two distinct improvements: low voltage operation from V DC, and an Active Current Limit. Operating from a single V supply minimizes heat dissipation. Modular packaging makes it easy to integrate the P into your system. A separate laser diode power supply input lets you provide a higher compliance voltage. The Active Current Limit not only protects your laser diode, but ensures that you are operating with maximum stability. When the laser current reaches the level set by the Limit I Trimpot, the output disables and the Limit LED and Limit Status indicate the current limit has been reached. Two photodiode ranges provide variable sensitivities for optimum operation. You can maintain excellent stability when operating in both constant current and constant power mode. All trimpots and switches are easily accessible and offer precision control. A slow start circuit, mechanical shorting relay, and Active Current Limit offer maximum protection for your laser diode even when power is removed. December, 00 FEATURES 00 ma, 00 ma,. A, A and. A models Single supply operation: VDC Separate Laser Diode Supply input allows for fl exible compliance voltages up to VDC typical Manually adjust: Setpoint & Current Limit Constant Current or Constant Power Operation Photodiode Sensitivity Remotely: Adjust Setpoint Current with Analog Input Enable or Disable Output Monitor Laser Diode Current, Photodiode Current, and Laser Diode Limit Current Monitor Limit Status Supports all laser diode / photodiode pin confi gurations Safety is maximized: Slow start circuitry Mechanical relay protects even when power is removed Active Current Limit Integral Heatsink (Fan Assembly included with P0, P 000 and P00) e Figure Pin Layout and Descriptions CATHODE ANODE ANODE / SUPPLY GND ANALOG INPUT LIM LIM I STATUS AUX AUX V 0 Ordering Information P00 P00 P0 P000 P00 PEVAL P0000 P00 PKCH P0KCH P.KCH 00 ma Laser Diode Driver 00 ma Laser Diode Driver. A Laser Diode Driver A Laser Diode Driver. A Laser Diode Driver Evaluation PCB for P 00, 00, 0, 000, and 00 SEE SEPARATE DATASHEETS FOR MODELS BELOW 0 A Laser Diode Driver. A Laser Diode Driver A Laser Diode Driver 0 A Laser Diode Driver. A Laser Diode Driver NOTE: P0000 & P00 are DIP models with integrated heatsink. P.KCH, P0KCH and PKCH are chassis mount. A, 0 A and A models, respectively.
Figure Quick Connect Type A/B Laser Diode Short pin to pin when analog input not in use. SIGNAL GENERATOR 0 to (OPTIONAL) DVM 0 k (Pull Up Resistor required to monitor Open Drain output) ANALOG INPUT (LOW CURRENT) ( CURRENT) ( CURRENT) MONITOR STATUS P ANODE ANODE GND (INTERNALLY SHORTED) 0 0. F OR PAGE CLOSED = Enabled OPEN = Disabled
ELECTRICAL AND OPERATING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS RATING SYMBOL Supply Voltage V Supply Voltage (A High Compliance) Anode Supply Voltage (Type C Lasers) AUX V Operating Temperature (typical) T OPR Storage Temperature T STG Weight Size P00 P00 P0, P000 & P00 PARAMETER DRIVE CURRENT OUTPUT Output Current Max (see SOA Chart) Compliance Voltage ( V) Compliance Voltage Temperature Coeffi cient Short Term Stability, hour PHOTODIODE FEEDBACK High Range Low Range (Type A & B ONLY) Constant Power Output Stability EXTERNAL MODULATION Input Impedance Transfer Function (0 to V) Analog In Damage Limits Bandwidth, db Depth of Modulation at 00 khz POWER SUPPLY Maximum Internal Power Dissipation Quiescent Current MONITOR ACCURACY Monitor Voltage versus expected output current based on transfer function P00 0. < < < 00 < 00 0000 00 < 0.0 0 0 0 0 P00 0. < < < 00 < 00 0000 00 < 0.0 VALUE to. to 0 to. 0 to 0 to < 0.. x. x 0.. x. x.0. x. x. MODEL P0. < < < 00 < 00 0000 00 < 0.0 < < < 00 < 00 0000 00 < 0.0 UNIT Volts DC Volts DC Volts DC C C pounds inches P000 P00. < < < 00 < 00 0000 00 < 0.0 PAGE A V V ppm / C ppm A A % 00 0 000 000 M ma / V 0. V < ANALOG IN < Supply Voltage (pin 0) 0.V 00 0 0 00 0 0 0 0 0 00 0 0 UNITS khz % W ma % full scale Compliance Voltage will vary depending on power supply voltages. In high compliance mode, a maximum compliance voltage of volts will be obtained with 0 volts input. A maximum compliance voltage of volts will be obtained with volts input. See page for more detail. Modulation bandwidth in Constant Power mode will depend on photodiode response. It is typically 0% of Constant Current Bandwidth. NOTE: Photodiode manufacturer s current specifi cations vary by a large percentage. As pulse frequency increases on the analog input, the peaktopeak output amplitude diminishes. For example, these graphs show the waveform shape at 0 Hz and 00 khz. Depth of modulation continues to decrease after 00 khz. Full Current If a thermistor or TE module are case common with the laser diode, the P and temperature controller power supplies may need to be isolated from each other or a bipolar supply may be required. To drive. A, you may need to increase supply voltage to. V. Cable impedance at these currents may reduce voltage to the unit or to the load. 0 ma 00% Depth of Modulation at 0 Hz Consult the online Safe Operating Area (SOA) calculator for supply voltages exceeding VDC: http:///support/calculator/soa/soald.php % 00 % 0 % % 0 % 0% Depth of Modulation at 00 khz NOTE: Specifications for Rev. F of the P family are found on Page
PIN DESCRIPTIONS PIN NO. PIN DESCRIPTION AUX V AUX LIM I STATUS LIM ANALOG INPUT 0 V GND ANODE / SUPPLY ANODE CATHODE PAGE FUNCTION For TYPE C laser diodes only. See page. For TYPE C laser diodes only. See page. Enable Output Current = to V Disable Output Current = Ground or Floating LIMIT status. LIMIT 0. V. Normal Operation = High Impedance If Limit is detected, laser diode current will turn off, Limit I LED will light. Toggle to restart laser diode current. Current Limit Setpoint Monitor. Impedance = k Output 0 to. V NOTE: Current limit needs to be set 0. V above desired limit level. Additional notes for fi netuning the current limit can be found on page. Measurement ground. Low current return used only with MONITOR pins and ANALOG INPUT. Shorted to GND pin internally. Laser Diode Current Monitor. Impedance is k Output 0 to. V Power Monitor ( Current Monitor). Impedance = k Output 0 to. V Remote Setpoint or modulation input. Input impedance = M Input 0 to V. Connect ANALOG INPUT to when not in use. Signal should be between 0. V and (pin 0 0. V) to avoid damage to the electronics. Supply voltage to control electronics. Min. V Max. V Power supply ground. Used with V input for high current return. Laser Diode Anode and Laser Diode Supply connection. Recommended Supply for single laser is V. Maximum 0 V. CAUTION: Too high a voltage may damage the P. Laser Diode Cathode For Type A or B laser diodes, Photodiode Anode. Tie to Pin ( Aux) for Type C laser diodes. See page. For TYPE C laser diodes only. See page. LASER DIODE TYPES The following laser diode / photodiode confi gurations are common Type A, Type B, and Type C. Setup and operation vary according to your type of laser diode. Please identify which laser diode you will be using with the P and follow the appropriate operating instructions. Operating instructions for lasers of Type A or B are detailed on pages 0. Operating instructions for Type C Lasers are detailed on pages. Type A Laser Diode Type B Laser Diode Type C Laser Diode Short Laser Diode Anode to Photodiode Cathode Laser Diode Anode & Photodiode Cathode Common Common Cathode Isolated Photodiode Laser Diode Cathode & Photodiode Anode Common Common Anode
TESTING SPECIFICATIONS Timing Characteristics Symbol t ON t OFF t SLOWSTART Parameter On Time Off Time Slow Start Time Test Points Load Load Load Test Conditions * P00 0 P00.0 P0 0. P000 0. P00 0. P00 0 P00.0 P0 0. P000 0. P00 0. P00 0 P00.0 P0 0. P000 0. P00 0. Test Setup for Parameter Measurement SIGNAL GENERATOR (OPTIONAL) DVM 0 k (Pull Up Resistor required to monitor Open Drain output) 0 to ANALOG INPUT (LOW CURRENT) ( CURRENT) ( CURRENT) MONITOR STATUS ANODE GND (INTERNALLY SHORTED) 0 Typ sec sec sec sec sec sec sec sec sec sec. sec. sec. sec. sec. sec CLOSED = Enabled TEST LOAD 0. F Specifications for Rev. F of the P Series P00 0 P00.0 P0 0. P000 0. P00 0 P00.0 P0 0. P000 0. P00 0 P00.0 P0 0. P000 0. t ON t OFF t SLOWSTART Test Load for P00, P00, P0, P000 & P00 For testing with currents <.0 A, an International Rectifier 0SQ can be used. Verify current rating prior to operation. 0SQ 0SQ. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec. sec Bandwidth Resistor * See Timing Characteristics Chart, Test Conditions column for applicable values. PAGE khz 00 khz 00 khz 00 khz Slow Start Timing Large signal frequency response 0 khz square wave response Current Limit Operation
SAFE OPERATING AREA & HEATSINK REQUIREMENTS 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:///support/calculator/soa/soald.php. PAGE 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: Device: P000 V s = 0 volts V = volts Load I Load =. amps Follow these steps:. Determine the maximum voltage drop across the driver, V s V Load, and mark on the X axis. Example: 0 volts volts = volts, Point A. Determine the maximum current, I Load, through the driver and mark on the Y axis: (. amps, Point B). Draw a horizontal line through Point B across the chart. (Line BB). Draw a vertical line from Point A to the maximum current line indicated by Line BB.. Mark V S on the X axis. (Point C). 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 within the Safe Operating Area for this device.
SAFE OPERATING AREA & HEATSINK REQUIREMENTS PAGE The charts on this page can be used to determine if your design falls within the Safe Operating Area (SOA) for the P series driver that you are using. For an example of how to use these charts, reference the previous page. There is also an online Safe Operating Area calculator available at: http:///support/calculator/soa/soald.php.
TYPICAL WIRING for TYPE A or B LASER DIODE OPERATION OPERATION Short pin to pin when analog input not in use. SIGNAL GENERATOR 0 to (OPTIONAL) DVM 0 k (Pull Up Resistor required to monitor Open Drain output) EXTERNAL ADJUSTMENTS L P RANGE MODE H I ANALOG INPUT (LOW CURRENT) ( CURRENT) ( CURRENT) MONITOR STATUS Range L H Mode P I Switch Setting P 00 A 0000 A Constant Power Constant Current ANODE ANODE GND (INTERNALLY SHORTED) 0 0. F OR PAGE CLOSED = Enabled OPEN = Disabled CAUTION: DO NOT change switch positions while the output is enabled; doing so may damage your laser diode. OUTPUT ADJUS T LIMIT I ADJUS T OUTPUT ENABLED LIMIT I OUTPUT ADJUST: This turn trimpot adjusts the laser diode forward current in constant current mode and monitor photodiode current in constant power mode. ACTIVE ADJUST: This turn trimpot adjusts the maximum laser diode forward current. P SERIES LASER DIODE DR IVE R avelength Elec tronic s OUTPUT ENABLED LED: Illuminates green when laser diode current is enabled. The LED is not lit when the output is disabled. LIMIT I LED: Illuminates red when output current has reached the limit current level (as set by LIMIT I Adjust Trimpot). LED will stay red until the output has been disabled then reenabled with the condition corrected.
ALTERNATE WIRING for TYPE A or B LASER DIODE OPERATION HIGH COMPLIANCE VOLTAGE OPERATION SIGNAL GENERATOR (OPTIONAL) DVM Short pin to pin when analog input not in use. 0k (Pull Up Resistor required to monitor Open Drain output) 0 to ANALOG INPUT (LOW CURRENT) ( CURRENT) ( CURRENT) MONITOR STATUS P ANODE ANODE GND (INTERNALLY SHORTED) 0 Closed = Enabled Open = Disabled 0. F 0 F OR LM REG. 0. F HEATSINKING REQUIRED 0 F PAGE V to 0V This circuit shows how to use a single power supply. The LM ( V Regulator) circuit can be replaced with a separate power supply. NEGATIVE SUPPLY OPERATION SIGNAL GENERATOR (OPTIONAL) DVM V to 0V ANALOG INPUT (LOW CURRENT) P ANODE ANODE 0. F OR CLOSED = Enabled OPEN = DIsabled 0k (Pull Up Resistor required to monitor Open Drain output) ( CURRENT) ( CURRENT) MONITOR STATUS GND (INTERNALLY SHORTED) 0 [V] [GND] V
OPERATING PROCEDURES for TYPE A or B LASER DIODES CONSTANT CURRENT MODE With the Output Disabled: () Configure Mode Switch to I. [switch on top of P] () Set Limit Current: Monitor the Lim I Monitor voltage and adjust the Current Limit trimpot clockwise (CW) until the voltage on the Lim I Monitor corresponds to the desired level. NOTE: The current limit circuit triggers slightly before the expected limit level. To fi ne tune the limit, add an offset voltage to the setting per the graph on page 0. Limit Current and I Monitor Transfer Functions P00 0 ma / Volt P00 00 ma / Volt P0 00 ma / Volt P000 A / Volt P00. A / Volt Once Current Limit is detected, the output will turn off and the LIM I led will illuminate red. The LIM I Status voltage and LIM I LED will stay on until the Enable is toggled off then on, and the error no longer exists. () Set Operating Current. Use the transfer function from step to calculate the desired current. Monitor the voltage on the I Monitor pin. With the Output Adjust trimpot fully counterclockwise (CCW), enable the output. Slowly adjust the OUTPUT ADJUST trimpot CW until the desired voltage is measured on the I Monitor pin. () Monitor the Photodiode (optional). If the Photodiode is connected to the laser diode, check the voltage on the P Monitor pin. The switch on top of the P will determine the output transfer voltage by the position of the switch: L = 00 ma / V H = ma / V ( 00 A range) (0 000 A range) () Analog Input: This input is designed for analog signals only and is not recommended for use with TTL signals. You can either input a DC voltage for remote current setpoint control or use this input to modulate the laser diode. The total setpoint voltage is the sum of the Analog Input voltage and the voltage introduced by the onboard trimpot. The input transfer function will depend on the P model in use. Model P00 P00 P0 P000 P00 Transfer Function 0 ma / Volt 00 ma / Volt 0 ma / Volt A / Volt. A / Volt CONSTANT POWER MODE With the Output Disabled: PAGE 0 () Configure Mode Switch to P. [switch on top of P] () Set Limit Current: Monitor the Lim I Monitor voltage and adjust the Current Limit trimpot clockwise until the voltage on the Lim I Monitor corresponds to the desired level. NOTE: The current limit circuit triggers slightly before the expected limit level. To fi ne tune the limit, add an offset voltage to the setting per the graph on page 0. Limit Current and I Monitor Transfer Functions P00 0 ma / Volt P00 00 ma / Volt P0 00 ma / Volt P000 A / Volt P00. A / Volt Once Current Limit is detected, the output will turn off and the LIM I led will illuminate red. The LIM I Status voltage and LIM I LED will stay on until the Enable is toggled off then on and the error no longer exists. () Set the output power. Determine the photodiode current from data provided with your laser diode. Monitor the voltage on the P Monitor pin. Set the Range Switch for the appropriate photodiode current L = 00 A H = 0 000 A With the Output Adjust trimpot fully CCW, enable the output. When the laser reaches threshold, the photodiode current changes abruptly and rises quickly. Adjust the OUTPUT ADJUST trimpot slowly until the voltage on the P Monitor pin corresponds to the desired photodiode current. Transfer functions for Low and High Photodiode mode are: L = 00 ma / V H = ma / V () Analog Input: This input is designed for analog signals only and is not recommended for use with TTL signals. You can either input a DC voltage for remote current setpoint control or use this input to modulate the laser diode. The total setpoint voltage is the sum of the Analog Input voltage and the voltage introduced by the onboard trimpot. The input transfer function is the same for all models and depends on the RANGE switch setting. L = 00 ma / V H = ma / V
PAGE OPERATING PROCEDURES: PEVAL PCB with Type A/B Laser Diodes Monitor Limit Current Use a DVM across LIM (Pin ) and (Pin ) to measure the Limit Current setting. Screw Lock Connector We recommend AWG wire minimum for connections to the screw lock connector. Type Select Jumper Remove jumper for Type A or B laser diode operation. Jumper only for Type C laser diodes. Factory Default = JUMPER REMOVED Supply Shorting Bar To tie (Pin 0) to SUPPLY (Pin ), install this shorting bar. Factory Default = JUMPER INSTALLED POWER ON Power Switch & LED The GREEN LED will light when DC power is applied. LIM I MON CATHODE ANODE ANODE/ SUPPLY GND ANALOG INPUT LIM LIM I STATUS OFF Monitor Selection With a DVM attached to MONITOR (either Pin or ) and (Pin ), toggle switch to read laser diode forward current or photodiode current. AUX AUX V MONITOR ON INPUT VDC 0 L P MODE OUTPUT ADJUST LIMIT I ADJUST OUTPUT ENABLED LIMIT I LASER ENABLE RANGE H ON P SERIES LASER DIODE DRIVER Wavelength Electronics I LASER DISABLE Output Enable/Disable When DC power is applied, the output current can be enabled by setting this switch to Laser Enabled. Toggle this switch to clear a Current Limit error. Mechanical Support / Grounding Screw A tapped hole in the heatsink accepts a 0 x / screw from the bottom of the PCB. Grounding the heatsink with this screw will reduce fan noise on the P0, P000, and P00. This switch applies DC power to the P. Note that if the output is not also enabled, no output current will fl ow. V Input (Option ) V Input: Two inputs are available. If using a. mm connector (such as provided with the PWRPAKV), use the DC input next to the power switch. Otherwise, use the screw lock connector, pins 0 &. Monitors: To monitor Limit Current, Laser Diode or Photodiode Current, use for the negative input of the DVM and either LIM I MONITOR or MONITOR for the positive input. The switch set to PMONITOR measures photodiode current. IMONITOR measures laser diode current. Compliance Voltage: If a single laser diode is to be operated, install the jumper on the bar to short SUPPLY with V. For higher compliance voltage, remove the jumper and provide voltage to Pin via the screw lock connector. See High Compliance Voltage Operation on page. : The switch enables and disables output current to the laser diode. Toggle this switch to clear a Current Limit error.
TYPICAL WIRING for TYPE C LASER DIODES SIGNAL GENERATOR (OPTIONAL) Short pin to pin when analog input not in use. DVM 0k (Pull Up Resistor required to monitor Open Drain output) 0 to ANALOG INPUT ANODE (LOW CURRENT) ( CURRENT) ( CURRENT) MONITOR STATUS AUX P CATHODE ANODE 0 GND (INTERNALLY SHORTED) AUX V CLOSED = Enabled OPEN = Disabled OR 0 F LM REG. 0. F HEATSINKING REQUIRED 0 F This circuit shows how to use a single power supply. The LM ( V Regulator) circuit can be replaced with a separate power supply. PAGE to V AUX V EXTERNAL ADJUSTMENTS Range L Mode P I Switch Setting This switch must be set in the L position for Type C laser diodes. The photodiode range is 00 A. Constant Power Constant Current CAUTION: DO NOT change switch positions while the output is enabled; doing so may damage your laser diode. OUTPUT ADJUST: This turn trimpot adjusts the laser diode forward current in constant current mode and monitor photodiode current in constant power mode. ACTIVE ADJUST: This turn trimpot adjusts the maximum laser diode forward current. OUTPUT ENABLED LED: Illuminates green when laser diode current is enabled. The LED is not lit when the output is disabled. LIMIT I LED: Illuminates red when output current has reached the limit current level (as set by LIMIT I Adjust Trimpot). LED will stay red until the output has been disabled then reenabled with the condition corrected.
OPERATING PROCEDURES for TYPE C LASER DIODES CONSTANT CURRENT MODE With the Output Disabled: () Configure Mode Switch to I. [switch on top of P] () Set Limit Current: Monitor the voltage on the Lim I Monitor pin and adjust Current Limit trimpot clockwise until the voltage on the Lim I Monitor pin corresponds to the desired level. NOTE: The current limit circuit triggers slightly before the expected limit level. To fi ne tune the limit, add an offset voltage to the setting per the graph on page 0. Limit Current and I Monitor Transfer Functions P00 0 ma / Volt P00 00 ma / Volt P0 00 ma / Volt P000 A / Volt P00. A / Volt Once Current Limit is detected, the output will turn off and the LIM I led will illuminate red. The LIM I Status voltage and LIM I LED will stay on until the Enable is toggled off then on, and the error no longer exists. () Set Operating Current. Use the transfer function from step to calculate the desired current. Monitor the voltage on the I Monitor pin. With the OUTPUT ADJUST trimpot fully CCW, enable the output. Slowly adjust the OUTPUT ADJUST trimpot CW until the desired voltage is measured on the I Monitor pin. () Monitor the Photodiode (optional). If the Photodiode is connected to the laser diode, monitor the P Monitor voltage. The switch on top of the P should be set to L (High mode (Hi) is not available for type C confi gurations.): L = 00 ma / V () Analog Input: This input is designed for analog signals only and is not recommended for use with TTL signals. You can either input a DC voltage for remote current setpoint control or use this input to modulate the laser diode. The total setpoint voltage is the sum of the Analog Input voltage and the voltage introduced by the onboard trimpot. The input transfer function will depend on the P model in use. Model P00 P00 P0 P000 P00 Transfer Function 0 ma / Volt 00 ma / Volt 0 ma / Volt A / Volt. A / Volt CONSTANT POWER MODE PAGE With the Output Disabled: () Configure Mode Switch to P. [switch on top of P] () Set Limit Current: Monitor the voltage on the Lim I Monitor pin and adjust Current Limit trimpot clockwise until the voltage on the Lim I Monitor pin corresponds to the desired level. NOTE: The current limit circuit triggers slightly before the expected limit level. To fi ne tune the limit, add an offset voltage to the setting per the graph on page 0. Limit Current and I Monitor Transfer Functions P00 0 ma / Volt P00 00 ma / Volt P0 00 ma / Volt P000 A / Volt P00. A / Volt Once Current Limit is detected, the output will turn off and the LIM I led will illuminate red. The LIM I Status voltage and LIM I LED will stay on until the Enable is toggled off then on and the error no longer exists. () Set the output power. Determine the photodiode current from data provided with your laser diode. Monitor the voltage on P Monitor. One photodiode range is available. Set the Range Switch to L. L Range = 00 A With the Output Adjust trimpot fully CCW, enable the output. When the laser reaches threshold, the photodiode current changes abruptly and rises quickly. Adjust the OUTPUT ADJUST trimpot slowly until the voltage on P Monitor corresponds to the desired photodiode current. The transfer function is: L = 00 ma / V This can be adjusted with a resistor (R) connected between Cathode and AUX V. The new range can be calculated with: RANGE =. V / (R k ) [A] The new transfer function is: TF = / (R k ) [A / V] For example, a 00 resistor converts the RANGE to:. / (00 * 000 / (00 000)) = 00 ma max and the transfer function to: / (00 * 000 / (00 000)) =. ma / V () Analog Input: This input is designed for analog signals only and is not recommended for use with TTL signals. You can either input a DC voltage for remote current setpoint control or use this input to modulate the laser diode. The total setpoint voltage is the sum of the Analog Input voltage and the voltage introduced by the onboard trimpot. The input transfer function for all models is: 00 ma / V. Note that the transfer function will change if you change the photodiode RANGE. The new transfer function is RANGE / V.
OPERATING PROCEDURES: PPCB with Type C Laser Diodes Monitor Selection With a DVM attached to MONITOR Monitor Limit Current (either Pin or ) and (Pin ), Use a DVM across LIM toggle switch to read laser diode forward (Pin ) and (Pin ) to current or photodiode current. measure the Limit Current setting. Screw Lock Connector We recommend AWG wire minimum for connections to the screw lock connector. Install jumper for Type C laser diodes. This ties Anode (Pin ) to AUX (Pin ). Factory Default = JUMPER REMOVED To Operate a Photodiode Add AUX V of to VDC GND () AUX V () Supply Shorting Bar To tie V (Pin 0) to SUPPLY (Pin ), install this shorting bar. Factory Default = JUMPER INSTALLED Power Switch & LED The GREEN LED will light when DC power is applied. POWER ON LIM I MON CATHODE ANODE ANODE/ SUPPLY GND ANALOG INPUT LIM LIM I STATUS OFF AUX AUX V MONITOR ON INPUT VDC 0 L P MODE OUTPUT ADJUST LIMIT I ADJUST OUTPUT ENABLED LIMIT I LASER ENABLE RANGE H ON P SERIES LASER DIODE DRIVER Wavelength Electronics I LASER DISABLE PAGE Output Enable/Disable When DC power is applied, the output current can be enabled by setting this switch to Laser Enabled. Toggle this switch to clear a Current Limit error. Mechanical Support / Grounding Screw A tapped hole in the heatsink accepts a 0 x / screw from the bottom of the PCB. Grounding the heatsink with this screw will reduce fan noise on the P0, P000, and P00. This switch applies DC power to the P. Note that if the output is not also enabled, no output current will fl ow. V Input: Two inputs are available. If using a. mm connector (such as provided with the PWRPAKV), use the DC input next to the power switch. Otherwise, use the screw lock connector, pins 0 &. Compliance Voltage: If a single laser diode is to be operated, install the jumper on the bar to short SUPPLY with V. For higher compliance voltage, remove the jumper and provide voltage to Pin via the screw lock connector. V Input (Option ) : The switch enables and disables output current to the laser diode. Toggle this switch to clear a Current Limit error. Photodiode Feedback: To use photodiode feedback, you must jumper AUX to ANODE. A jumper is provided. Monitors: To monitor Limit Current, Laser Diode or Photodiode Current, use for the negative input of the DVM and either LIM or MONITOR for the positive input. The switch set to PMONITOR measures photodiode current. IMONITOR measures laser diode current. To Operate a Photodiode: To use photodiode feedback, you must provide AUX V of V to V across AUX V (Pin ) and GND (Pin ) of the screw lock connector.
APPLICATION NOTES Remote Status LED circuit A resistor is in series with the open drain output of the LIM I Status pin, so an external LED can be connected directly to the LIM I Status pin as shown. V LIM I Status External or Remote Limit LED External Trimpot Circuit Recommended circuit when an external trimpot is used to control the P output current. Bandgap Reference (.0 V maximum from ) [LM or LM00] Change Range for TYPE A or B laser diodes Put a resistor across the Anode and Common pins to modify the range of the P. Range = L Range = H. V * 0. V * 0 Range = [μa] Range = [μa] R kω R 00 Ω Transfer 0 Transfer 0 = [μa / V] = [μa / V] Function R kω Function R 00 Ω R kω kω Ω Range Switch Anode Common R * 000 = R kω R 000 = R * 00 R 00 kω V (0) ANALOG INPUT () R () R = 0k to 00 kω R MONITORS 0kΩ 0kΩ 0kΩ 0kΩ CALIBRATED CURRENT SETPOINT PAGE Laser Diode Protection when using a long cable With a cable longer than two feet, add a Schottky diode across the laser diode. Anode Cathode Cable > feet Schottky Diode (N) Laser Diode Filter the P Output If you don t need to modulate, you can reduce the noise by fi ltering the output current. Anode Cathode Monitor Calibration Circuit A small offset may be present when measuring the P Monitor, I Monitor or LIM I Monitor voltage with respect to the actual output. Add this circuit to remove any offset. 0 μf Tantalum 0. μf Schottky Diode (N) Laser Diode Change the Modulation Transfer Function Cable Lengths with Currents Greater than A VIN R R ANALOG INPUT The length and gauge of cable from the power supply or to the laser diode can impact performance. The resistance and inductance of the wire can reduce bandwidth or cause the voltage to the P to droop. New Transfer Function New Transfer Function = Keep R and R below 00 kω for maximum accuracy. R Old Transfer Function R R * Example: (for P00) R = kω R = kω = 0 ma / V = ma / V * If V is tied to Anode and I OUT starts to oscillate as setpoint voltage approaches the limit setting (within 0. V), then your cables are too long. If you cannot shorten the cables, place a capacitor across V and ground (~0 F) to minimize droop. Always twist the wire pairs to eliminate reactance. Fine Tuning Deep Modulation If the analog modulation input is near the rail (>. V), output current signal response may be insufficient. Performance may be improved by connecting a quality lowesr 0 F, V electrolytic capacitor between the power terminals ( VDC and GND). This decoupling capacitor should be directly connected at the unit.
APPLICATION NOTES Power Supply and Noise The P Series Laser Diode Drivers are designed for stable, low noise operation. The power supply you select will directly affect the noise performance of the driver. We recommend using a regulated, linear supply for optimum performance. Depending on your requirements, you may be able to use a switching power supply. Each case must be evaluated independently because a switching power supply will affect noise, transient, and stability performance. Wavelength Electronics offers an evaluation kit and power supplies for easy configuration and operation. Fine Tuning Your Limit Current Setting PAGE Fan Electrical Noise in P000 and 00 The P000 and 00 models are equipped with a V fan that cools the heatsink. The fan in some cases may create electrical noise. To reduce the electrical noise level you must connect the heatsink to earth/chassis ground or the system ground (power supply common). To ground the heatsink you need to connect ground to the tapped hole in the bottom of the heatsink. The limit current circuit contains a small amount of hysteresis, which causes the limit current to trip slightly before expected. If the P current is close to the limit setpoint this hysteresis may affect operation. To compensate, a small offset voltage can be added to the limit current setting based on the Hysteresis offset chart above. Example: P000 with a current limit of. Amps = 0% of maximum current HO = Hysteresis Offset = 0. V at 0% The transfer function for P000 limit current monitor is A / V as given on pages and. V LIM = I LIM A / V HO =. V 0. V =. V Grounding Schemes CAUTION: If you plan to operate the P with any Wavelength temperature controller, you may need to use separate power supplies. If the TE cooler or thermistor is connected to the laser diode, you must either use two separate power supplies and let each fl oat independently of the other or use a bipolar power supply. CAUTION: IF LASER DIODE AND PHOTODIODE ARE ISOLATED (TYPE B LASER DIODE) Short the laser diode anode to the photodiode cathode. The P Series Laser Diode Drivers require the photodiode to be connected to the laser diode. If no connection is made between the laser diode and the photodiode, then the P will not operate properly in constant power mode, and the power monitor will not read the proper photodiode current. Some laser diode packages short either pin of the laser diode to the case, which may connect the pin to earth ground through system hardware. Special attention to the details of grounding will ensure safe operation. We offer the following defi nitions and options: DC POWER SUPPLY Laser Diode YES YES YES YES NO! Earth Ground on USA VAC wall socket EARTH Common or Instrument Ground Unless Earth and Instrument Ground are connected via the power supply, Instrument Ground is floating with respect to Earth Ground P Current Source V Example Grounding Configurations
MECHANICAL SPECIFICATIONS* OUTPUT ADJUST LIMIT I ADJUST OUTPUT ENABLED." [.mm] P SERIES LASER DIODE DRIVER.00" [.mm] avelength L P RANGE Electronics H I ON MODE LIMIT I 0." [.mm]." [.mm] 0." [0.mm] P00 ONLY." [.mm] ON.0" [.mm].0" [.mm] P00 ONLY 0." [.0mm]." [.0mm] P0, P000 & P00 ONLY 0." [.mm] 0." [.mm] 0." [0.mm]." [.mm] 0." [.mm].0" [.mm]." [0.mm] P0, P000 AND P00 PAGE 0.0" [.mm] 0.0" [.mm].00" [0.mm] PCB Layout Pattern Top View 0." [.mm] DIA (in PCB for # screw to secure unit to PCB) Use 0 x /" with 0.0" PCB material.." [.mm]." [.mm] 0." [.mm] 0.0' [0.mm] SQ. PINS ( TOTAL) Min. 0.0" [0.mm] DIA holes in PCB " [.mm] 0.0" [.mm] 0.0" [.mm] 0.00" [.mm] TYPICAL SPACING *All tolerances are ±% (inches, [mm])
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 0 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 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. WAVELENGTH ELECTRONICS, INC. Evergreen Drive Bozeman, Montana, web: phone: (0) 0 Sales/Tech Support fax: (0) email: sales@teamwavelength.com PAGE 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 photocopied, reproduced, or 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 features 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. REVISION REV. F REV. G REV. H REV. I REV. J & REV. K REV. L REVISION HISTORY DATE Nov0 Feb0 Jun0 Aug0 Dec0 & Feb0 Dec0 NOTES Monitor Accuracy data updated Updated Mechanical specifications Updated pinout diagram page Updated links to support new website Applies to Rev. G changes. Improved bandwidth, lowered noise Added. A models