Wavelength Electronics LFI-3500 Series User`s guide

TM
LFI 4500 Series
Laser Diode Drivers
User’s Guide
2
LFI-4500
Laser Diode Driver
User’s Guide
Publication number 92-130004D
© Copyright 1996, 1997, Wavelength Electronics, Inc.
P O Box 865, Bozeman, MT 59771
All Rights Reserved
Printed in U. S. A.
3
Laser Diode Drivers
The 4500 series of laser diode drivers offers an unprecedented combination of safety,
performance, and value. Low noise, stable operation makes these flexible instruments ideal for
even the most demanding applications. Any combination of LFI modules (both laser diode
drivers and temperature controllers) can be interconnected to provide a complete laser diode
control solution.
Extensive protection features are incorporated into the 4500 series to protect your laser diode
from damage. The output control circuitry includes a shorting relay which protects the laser
diode when the output is off or the unit is powered down. The slow start circuit waits three
seconds and then safely ramps the output to the preset operating level. To prevent thermal
damage to your laser diode, the LFI-4500 series output can be disabled by the LFI-3500
temperature controller via the analog interface input. A unique AC power monitor circuit disables
the output if AC power is above or below the recommended input level.
Simple to use front panel controls make the 4500 series easy to operate. Highly visible LEDs
indicate errors that effect the output, on/off status, and current limit condition. Control the laser
diode forward current or monitor photodiode current using the linear ten-turn potentiometer. The
current limit setting is fully independent and is set using a twelve-turn trimpot on the front panel.
Interlock any combination of LFI-4500 series laser diode drivers or LFI-3500 series
temperature controllers without additional hardware. Two or more modules mount into a 19" rack
with optional rack mount kits
KEY FEATURES ...
•
•
•
•
•
•
•
Low noise, stable current source (<20 ppm)
Constant Current and Constant Power control modes
Five models deliver from below 200mA to 6.5 Amps
Works with all LD/PD configurations
Easy to adjust, fully independent current limit
Slow turn-on and comprehensive laser protection circuitry
Operates on standard AC voltages
... the WAVELENGTH Advantage
Low cost, flexible instrument
Easy setup- Intuitive front and rear panels
Display laser diode current and voltage, limit current, photodiode current
Select photodiode range & modulation range for greatest sensitivity
Four Selectable output filters allow maximum performance in CW or modulated mode
Interface to the LFI 3500 Temperature Controller to protect laser diode from thermal runaway
conditions
Comprehensive Analog Interface includes:
Buffered monitors: LD current & voltage, PD current, and LIMIT current
Remote output ON/OFF control
External control of operating current
"Open Drain" ON/OFF and error status outputs
Laser safety interlock
4
LFI 4500 Series Selection Guide
Model
Description
LFI-4502
LFI-4505
LFI-4510
LFI-4532
LFI-4565
200 mA Laser Diode Driver
500 mA Laser Diode Driver
1 Amp Laser Diode Driver
3.25 Amp Laser Diode Driver
6.5 Amp Laser Diode Driver
Each model includes: 9&15 pin D-sub plugs with shielded covers and hardware, user
guide, and AC power cord.
Cable – Selection Guide
Model
Description
Output cable, single connector (9 pin D-sub plug)
CAL-105
One end connectorized one end
unterminated
CAL-106
Output cable, double connector (9 pin D-sub plugs)
Both ends connectorized
All cables are 1 meter long.
Rack Mount Kits- Selection Guide
Model
Description
Rack mount kit for two LFI modules
RMK-502
Includes two
5 1/4" panels
RMK-503
Rack mount kit for three LFI modules
Includes one
1" panel and one
5 1/4" panel
RMK-504
Rack mount kit for four LFI modules
Includes two
1" panels
All RMK kits include (4)- 1/4-20 screws. No additional hardware is required to
attach rack mount brackets to LFI modules.
5
Default Configuration from the Factory
The following are the factory default settings.
Rear Panel:
CONFIGURATION SWITCH:
OFF
1 2 3 4 5 6 7 8 9 10
ON
CONFIGURATION
Mode of Operation: Constant Current
Modulation Bandwidth: Fully limited
PD Current Range: 2000 µA
Modulation Sensitivity: 10:1
Modulation Input: Disabled
Front Panel:
Current Limit:
6
25 mA for LFI-4502
50 mA for LFI-4505
100 mA for LFI-4510
250 mA for LFI-4532 & LFI-4565
TABLE OF CONTENTS
Default Configuration from the Factory____________6
Safety Summary ______________________________8
Front Panel At a Glance _______________________10
Rear Panel At a Glance ________________________12
Preparing the Laser Diode Driver for Use _________15
Operating Guidelines _________________________16
Operation in Constant Current Mode __________ 16
Operation in Constant Power Mode ___________ 19
Set Current Limit ___________________________ 22
Further Information ___________________________23
Error and Status Indicators __________________ 23
Analog Interface ___________________________ 24
Constructing a Dummy Load _________________ 26
General Specifications ______________________ 27
Electrical Specifications_____________________ 28
Mechanical Specifications ___________________ 29
Cable Accessories _________________________ 30
Warranty ____________________________________31
7
Safety Summary
Do not install substitute parts or perform any unauthorized modification to the product.
Return the product to Wavelength Electronics for service and repair to ensure that
safety features are maintained.
Do not use this product beyond its specifications.
SYMBOL
DEFINITION OF SYMBOL
WARNING
Calls attention to a procedure, practice, or condition that could
possibly cause bodily injury or death.
!
ATTENTION
Ce symbole signale une procédure ou des conditions
dangereuses pouvant entraîner des blessures corporelles ou la
mort.
VORSICHT!
Nichtbeachtung der Hinweise können die körperliche
Unversehrtheit beeinträchtigen oder zum Tod führen.
NOTE!
Calls attention to a procedure, practice, or condition that could
possibly cause damage to equipment or devices being
operated by this equipment.
CAUTION Risk of Electric Shock
ATTENTION Risque d’Electrocution
VORSICHT Hochspannung
Earth Ground Symbol
Chassis Ground Symbol
8
NOTE!
Complete all operational steps in the order provided. Skipping
a step can result in damage to the laser diode. Start with the
section appropriate to the mode of operation you are using.
WARNING
For continued protection against fire, replace line fuse only with
fuse specified, type and rating.
!
ATTENTION
Pour une protection permanente contre les risques d’incendie,
ne remplacer les fusibles secteur que par des fusibles
conformes aux spécifications.
VORSICHT
Defekte Sicherungen sind nur durch die angegeben Typen und
mit den spezifizierten Werten zu ersetzen um die Sicherheit des
Gerätes zu gewährleisten.
CAUTION
RISK OF ELECTRICAL SHOCK. Do not power on this
instrument if the case is damaged or any of the covers or
panels are removed.
NO USER SERVICEABLE PARTS
INSIDE.
ATTENTION
Risque d’Electrocution. Ne pas mettre sous tension cet
instrument si le boîtier est endommagé ou si les capots ou les
faces sont retirés. Aucun composant réparable par l’utilisateur.
VORSICHT
Hochspannung.
Im Falle eines Gerätedefektes oder bei
geöffneter Verkleidung Netzstecker ziehen! Gerät kann und
braucht vom Anwender nicht gewartet werden.
CAUTION
POSSIBLE ELECTRICAL SHOCK OR FIRE HAZARD. Do not
expose the LFI Laser Diode Driver to rain or moisture. Do not
operate this instrument in the presence of flammable gases or
fumes.
ATTENTION
Risque d’électrocution ou d’incendie.
Ne pas exposer
l’alimentation LFI à la pluie ou à l’humidité. Ne pas utiliser cet
instrument en présence de gaz inflammable ou de fumée.
VORSICHT
Brandgefahr und Gefahr eines elektrischen Schocks! Setzen
Sie das Gerät nicht dem Regen oder der Feuchtigkeit aus.
Schalten Sie das Gerät in der Gegenwart entflammbarer Gase
oder Dämpfe nicht ein!
9
Output Section:
Output Enable Button: This switch enables and disables the laser diode current source output.
When first enabled, the output current goes through a slow-start sequence. The slow start
will delay the output of current for three seconds then slowly ramp the output current
(approximately 500 ms) to the preset output current setting. While disabled, the LFI 4500
driver protects the laser diode by 1) shorting the laser diode with a relay, 2) taking the
setpoint to zero, and 3) bringing the limit current to a low standby current. The relay will also
short the laser diode when the unit is powered down. If an error occurs that shuts off the
output, this button must be pressed once to clear the error and again to enable the current.
Output On LED: This LED lights green whenever the output is enabled and current flows
through the laser diode.
Adjust Potentiometer: This ten-turn linear potentiometer is provided to adjust the Output
Setpoint for either constant current or constant power mode. This potentiometer adjusts
laser diode forward current in constant current mode and monitor photodiode current in
constant power mode.
Limit Current LED: This LED lights red whenever the laser diode output current is limited to the
adjustment set by the Limit Current Trimpot. The output current will remain in this state until
the setpoint is reduced below the Limit Current Trimpot setting. This condition does not
create an error to shut the output off.
Limit Current Trimpot: This trimpot adjusts the maximum current that can be delivered to the
laser diode. Adjusting the trimpot clockwise increases the Limit Current Setpoint.
Display Section:
3 1/2 Digit Display: This can be used to measure the laser diode forward current, the monitor
photodiode current, the actual limit current and limit current setpoint, and the laser diode
forward voltage.
Display Select Switch: The position of this switch determines what value is displayed on the 3
1/2 digit LED display.
2000µ
µA and 200µ
µA PD I: To display the monitor photodiode current, the switch is set to one
of these two positions. The switch position should be coordinated with the monitor
photodiode current setting on the Configuration Switch on the rear panel for maximum
resolution. To display the setpoint in constant power mode, rotate the Display Select
Switch to the appropriate position and hold in the Display Set Button.
LD I: This position displays the amount of current being sourced through the laser diode
with these resolutions:
LIMIT I MONITOR: This position displays the actual Limit Current flowing through the Limit
Current Source.
LIMIT I SETPOINT: This position displays the preset Limit Current Setpoint as set by the
Limit Current Trimpot.
LD V: This position displays the voltage across the laser diode load.
11
Rear Panel At A Glance
The following terms for the rear panel components will be referenced
throughout this manual.
Analog Input
Serial Number
6B4A1001
Output Connector
Analog Interface
Connector
Configuration Switch Bank
AC Fuse
Voltage Select Switch
AC Power Input
Output Connector Description
9 pin D-sub recp
Pin 1: Not Used
5
1
Pins 2 & 3: (Indicator -, Indicator+) These pins source 5 mA to an
external LED indicating the output is on.
Pins 4 & 5: (PD Anode, PD Cathode) These pins connect to the 9 OUTPUT 6
monitor photodiode. A monitor photodiode must be connected to
operate the laser diode driver in constant power mode.
Pins 6 & 9: (Laser Diode Anode) These two pins are jumpered for contact reliability and
increased current capacity. Use both pins for best performance.
Pins 7 & 8: (Laser Diode Cathode) These two pins are jumpered for contact reliability and
increased current capacity. Use both pins for best performance.
12
Configuration Switch Bank:
This ten position switch bank configures the mode of operation (constant current or constant
power), the bandwidth of the output current, the range of photodiode sensitivity, and the
modulation transfer function.
Switches 1, & 2: (Constant Current or Constant Power Mode of Operation One of these
switches must be on for proper operation. The following chart shows the positions for both
modes of operation:
Mode
Switch 1
Switch 2
Constant Current
ON
OFF
Constant Power
OFF
ON
If both switches are accidentally left OFF, the output current will be shunted around the laser
diode by the output control shunt MOSFETs.
NOTE!
If both switches are accidentally left ON, it is possible that
the laser diode forward current could reach the Limit Current
Setting.
Switches 3, 4, & 5: (330µ
µF, 10µ
µF, 1µ
µF filter capacitors) These switches select the type of
capacitive filtering across the laser diode load. All or none of these switches can be ON at one
time depending on the noise filtering and bandwidth requirements of the laser diode
application. A minimum of 0.1µF capacitance is always present across the laser diode. The
output current bandwidth will depend on the total output capacitance and impedance of the
laser diode load.
Switch 6: (Modulation Bandwidth) When this switch in ON, a single pole filter with a 3dB
break frequency of 32Hz is inserted into the path of the setpoint control signal for the output
control loop. This limits the bandwidth of the modulation signal to a frequency of less than
32Hz. This is extremely useful for very low noise applications such as spectroscopy and
interferometry.
Switches 7 & 8: (2000µ
µA or 200µ
µA Photodiode Current Sensitivity) This switch can configure
the photodiode transimpedance amplifier’s sensitivity. The following table shows the available
settings.
Sensitivity Range
Switch 7
Switch 8
ON
OFF
50 - 2000µA
OFF
ON
15 - 200 µA
OFF
OFF
1 - 20 µA
To increase the range to 20mA, set the switch for the 2000µA range and place a 10Ω resistor
across pins 5 and 6 of the Output Connector.
Switch 9: (Modulation Sensitivity) The modulation sensitivity can be controlled by this switch
position. The following table details the transfer functions for each model:
Switch 10: (Modulation Input Enable) This switch is used to enable or disable the modulation
input. When this switch is OFF, the modulation input is disabled and the output cannot be
controlled from the BNC or the Analog Interface Connector. When this switch is ON, the
modulation input is enabled and the output can be controlled by these external analog inputs.
13
Analog Interface Connector:
ANALOG
INPUT
50 Ω Terminator
8
1
15
9
BNC & 15 pin D-sub receptacle
ANALOG INTERFACE
Pins 1 & 2: (Analog Input+, Analog Input-) External analog input. The BNC is in
parallel, but isolated by two 1kΩ resistors. Either of the inputs can be used, but not
simultaneously.
Pins 3 & 4: (Interlock+, Interlock-) These pins must be shorted to turn the output
on. The interlock is required by the FDA 21 CFR section 1040.10 and 1040.11 for
operation of Class IIIB and IV lasers. The laser diode current output cannot be
enabled if these pins are not shorted (the resistance between pins must be less than
5kΩ).
Pins 5 & 6: (Error+, Error-) Connect to LFI-3500 temperature controller. If the
temperature controller is disabled for any reason, the laser diode driver output will
be disabled.
Pin 7: (Error Detect) Error status.
Pin 8: (On/Off Detect) On/Off status.
Pin 9: (Common) Common for pins 7, 8, & 10 .
Pin 10: (Remote On/Off) Remote On/Off control input.
Pin 11: (PD I) Photodiode current monitor.
Pin 12: (LD I) Laser Diode current monitor.
Pin 13: (Forward Voltage- Vf ) Monitors voltage across laser diode
Pin 14: (Limit I) Limit current monitor.
Pin 15: (Monitor Common) Common for pins 11-14.
14
Preparing the Laser Diode Driver for Use
Check the list of supplied items:
o
o
o
o
o
þ
One Power cord
One 9 pin D-Sub plug (solder cup), hood, and connecting hardware
One 15 pin D-Sub plug (solder cup), hood, and connecting hardware
One AC Fuse installed
One AC Fuse is shipped separately
This user’s Guide
Verify that the correct power-line fuse is installed and the
power-line voltage setting is correct.
The factory sets the following defaults based on the country of destination for
initial shipment:
Destination
Voltage Setting
Fuse Rating
US, Canada
UK
Continental Europe
Japan
115V
230V
230V
115V
2A
1A
1A
2A
For operation between 100 and 120VAC, install a 2 Amp slo-blow
5 x 20 mm fuse. Set the Voltage Select Switch to 115.
For operation between 220 and 240V operation, install a 1 Amp
slo-blow 5 x 20 mm fuse. Set the Voltage Select Switch to 230.
15
Step 4: Select the Modulation Input Bandwidth
When only DC control of the output is necessary, the noise performance can be
maximized by applying a single pole filter to the setpoint signal (the sum of the Adjust
Potentiometer and Modulation Input). This filter is inserted when Switch 6 is ON.
OFF
OFF
1 2 3 4 5 6 7 8 9 10
1 2 3 4 5 6 7 8 9 10
ON
ON
High
Bandwidth Mode
CONFIGURATION
Low
Bandwidth Mode
CONFIGURATION
Step 5: Select the Photodiode Range
If you connect a photodiode while in constant current mode, it will not be used in the
feedback loop, but you can monitor the photodiode current to determine the laser
diode power. For maximum sensitivity, three ranges of sensing are provided. If your
photodiode maximum current exceeds 200µA, use the wider range.
OFF
1 2 3 4 5 6 7 8 9 10
ON
Max PD current 2000µA
OFF
OFF
1 2 3 4 5 6 7 8 9 10
ON
1 2 3 4 5 6 7 8 9 10
ON
Max PD current 200µA
Max PD current 20µA
To increase the range to 20mA, set the switch for the 2000µA range and place a 10 Ω
resistor across pins 5 & 6 of the Output Connector.
Step 6: Select the Modulation Sensitivity & Enable or Disable Modulation
The sensitivity selection is provided to maximize modulation performance. The
modulation signal can be passed through as a 1:1 signal or attenuated by a 10:1
factor. The following details the modulation transfer functions for each model.
Transfer Functions
Switch 9
Switch 9
MODEL
ON
OFF
LFI-4502
40mA / V
4 mA / V
LFI-4505
100 mA / V
10 mA / V
LFI-4510
200 mA / V
20 mA / V
LFI-4532
0.650 A / V
0.065 A / V
LFI-4565
1.3 A / V
0.13 A / V
OFF
1 2 3 4 5 6 7 8 9 10
1:1 modulation range with
modulation enabled.
ON
CONFIGURATION
Switch 10 either enables or disables modulation. Modulation is disabled when Switch
10 is OFF. It is enabled when Switch 10 is ON.
17
Step 4: Select the Modulation Input Bandwidth
When only DC control of the output is necessary, the noise performance can be
maximized by applying a single pole filter to the setpoint signal (the sum of the Adjust
Potentiometer and Modulation Input). This filter is inserted when Switch 6 is ON.
OFF
OFF
1 2 3 4 5 6 7 8 9 10
1 2 3 4 5 6 7 8 9 10
ON
ON
High
Bandwidth Mode
CONFIGURATION
Low
Bandwidth Mode
CONFIGURATION
Step 5: Select the Photodiode Range
You must have a monitor photodiode to operate in constant power mode. For
maximum sensitivity, two ranges of sensing are provided. If your photodiode
maximum current exceeds 200µA, use the wider range.
OFF
OFF
1 2 3 4 5 6 7 8 9 10
ON
OFF
1 2 3 4 5 6 7 8 9 10
ON
Max PD current 2000µA
1 2 3 4 5 6 7 8 9 10
ON
Max PD current 200µA
Max PD current 20µA
To increase the range to 20mA, set the switch for the 2000µA range and place a 10 Ω
resistor across pins 5 & 6 of the Output Connector.
Step 6: Select the Modulation Sensitivity & Enable or Disable Modulation
The sensitivity selection is provided to maximize modulation performance. The
modulation signal can be passed through as a 1:1 signal or attenuated by a 10:1
factor. The following details the modulation transfer functions for constant power
mode.
PD Range
2000 µA Range
200 µA Range
Transfer Functions
Switch 9
Switch 9
ON
OFF
400 µA / V
40 µA / V
40 µA / V
4 µA / V
OFF
1 2 3 4 5 6 7 8 9 10
1:1 modulation with
modulation enabled
ON
CONFIGURATION
Switch 10 either enables or disables modulation. Modulation is disabled when Switch
10 is OFF. It is enabled when Switch 10 is ON.
20
Error and Status Indicators
Several LED indicators and a beeper are used to determine the status of the
controller.
Status Section
Power LED: This LED lights green whenever the AC Power Switch on the front panel
is depressed and AC power is supplied to the unit.
Remote Error LED: This LED lights red whenever an error triggered by an LFI-3500
Temperature Controller is detected on the Analog Interface Connector on the rear
panel. The output current is automatically switched off when a Remote Error
condition occurs. Once the error is corrected, the Output On Button must be pressed
once to clear the error and again to enable the output.
Open Circuit LED: This LED lights red whenever the voltage measured across the
laser diode exceeds the compliance voltage for the driver. This condition can occur if
the impedance of the laser diode load is too high for the amount of current being
sourced through the device or if the laser diode load is disconnected from the output
connector. The output current is automatically switched off when an Open Circuit
condition occurs. Once the error is corrected, the Output On Button must be pressed
once to clear the error and again to enable the output.
Interlock / Keylock Error LED: This LED lights red whenever the interlock
connection is opened on the Analog Interface Connector on the rear panel, or when
the Key Switch is rotated to the disabled position. The output current is automatically
switched off when this error occurs. Once the error is corrected, the Output On Button
must be pressed once to clear the error and again to enable the output.
Output Section
On LED: This LED lights green whenever the Output On Button is toggled on. This
LED indicates that the output is now active and current will flow through the output
connector.
Limit LED: This LED lights red whenever the laser diode forward current is limited to
the adjustment setting on the Limit Current Trimpot (see page 22). The output current
will remain in this condition until the laser diode current falls below the Limit Current
Trimpot setting. This condition does not switch the output current off.
Beeper: The LFI beeps once whenever the output is turned on or off.
23
Analog Interface
Pins 1 & 2: (Mod+, Mod-) An external analog signal can be directly connected to these pins
(or the Analog BNC input) to remotely control the unit’s output current setpoint (Laser
diode forward current in constant current mode and monitor photodiode current in constant
power
mode).
This
input
is
configured
to
accept
± 10 V signals while withstanding inputs as large as ± 40V. Any input on these pins is
directly summed with the Output Current setpoint determined by the Adjust Potentiometer.
The impedance of this input is 60kΩ as measured across these terminals. A total of 30kΩ
isolates these inputs from pins 2 and 3 (LED Laser ON indicator) on the Output Connector.
NOTE!
If the laser diode is earth grounded only the Analog Input BNC may be
used to modulate the laser diode.
The shield side of the Analog BNC input is chassis grounded. Depending on how the
laser diode is grounded, three options are available:
1. If the modulation inputs are not used, install the 50 Ω terminator (provided with the unit) and
set the rear panel Configuration Switch positions 9 & 10 to OFF.
2. If the laser diode is not earth grounded, remove the 50 Ω BNC terminator and set the
Configuration Switch Position 10 to ON and 9 to the appropriate modulation sensitivity. The
signal can be input through either the Analog Input BNC or the Analog Interface Connector.
3. Only the Analog Input BNC may be used for modulating the laser diode when the
laser diode is earth grounded. Remove the 50 Ω BNC terminator, replace it with the
modulation source, and set the Configuration Switch Position 10 to ON and 9 to the
appropriate modulation sensitivity.
Pins 3 & 4: (Interlock+, Interlock-) These pins can be either shorted or connected to a
remote interlock as required by the FDA 21 CFR, Section 1040.10 and 1040.11 for
operation of Class IIIB and IV lasers. The impedance between pins 3 and 4 must be less
then 5kΩ for the interlock and keylock functions to operate correctly.
Pins 5 & 6: (Error+, Error-) These inputs were designed to connect to the LFI-3500 series
temperature controllers. Complementary outputs on the temperature controller are located
on the LFI-3500 analog interface connector. When these pins are connected to the LFI3500 temperature controller, if the temperature controller output is turned off (either by the
Output On Button or any error), the LFI-4500 laser diode driver output will be disabled.
These inputs require a minimum of 1.5 mA to trigger correctly. Three LFI-4500 laser diode
drivers can be connected to any one LFI-3500 simultaneously. This input is optically
isolated from the laser diode driver electronics.
NOTE!
LFI-4500’s output will NOT be disabled if
the LFI-3500 is in its powered off state
via its AC Power Switch.
Pins 7 & 9: (Error Detect, Common) This output is an open drain connection that remains
in a high impedance state while the output is enabled. If an error occurs that disables the
output, this output is forced into a low impedance state with respect to the common
connection (pin 9).
Pins 8 & 9: (On/Off Detect, Common) This pin is an open drain connection that remains in
a high impedance state when the output is disabled. When the output is enabled, this
output is forced into a low impedance state with respect to the common connection (pin 9).
Pins 9 & 10: (Common, Remote On/Off) These pins can be used to enable and disable the
output current source and directly effect the front panel Output On LED. A normally open
momentary switch with switch bounce less than 500 msec can be connected to these pins.
24
An open drain or open collector output from a digital section can be used to trigger this
input also, if the signal is momentary and does not exceed 500 msec.
Pins 11 & 15: (PD I, Monitor Common) This pin provides a buffered measurement of the
current produced by the laser diode’s monitor photodiode (pins 4 and 5 on the Output
Connector) and is referenced to pin 15. Its transfer function is dependent on the sensitivity
set by the Configuration Switch on the rear panel and is given by the following table. This
output is internally limited to 10mA maximum output current.
Transfer
PD Sensitivity
Function
2000µA
400µA / V
200µA
40 µA / V
20µA
4 µA / V
Pins 12 & 15: (LD I, Monitor Common) This pin provides a buffered measurement of the
forward laser diode current sourced through pins 6,9 and 7,8 of the Output Connector and
is referenced to pin 15. This output is internally limited to 10 mA maximum output current.
The transfer function depends on the model used:
Transfer
Model
Function
LFI-4502
40 mA / V
LFI-4505
100 mA / V
LFI-4510
200 mA / V
LFI-4532
0.650 A / V
LFI-4565
1.3 A / V
Pins 13 & 15: (Vf [Forward Voltage], Monitor Common) This pin provides a buffered
measurement of the laser diode forward voltage and is referenced to pin 15. Its transfer
function is 1 V / V. This output is internally limited to 10 mA maximum output current.
Pins 14 & 15: (Limit I Setpoint, Monitor Common) This pin provides a buffered
measurement of the limit current setpoint and is referenced to pin 15. Its transfer function is
model dependent and is the same as that of the laser diode forward current. This output is
internally limited to 10 mA maximum output current.
Transfer
Model
Function
LFI-4502
40 mA / V
LFI-4505
100 mA / V
LFI-4510
200 mA / V
LFI-4532
0.650 A / V
LFI-4565
1.3 A / V
NOTE!
The voltages on pins 11-15 are
also used to drive the front panel
3 ½ digit display. Faults or shorts
on these pins directly effect
measurements on the display.
25
LFI 4500 General Specifications
Power Supply:
115 or 230 VAC ±15% 50 or 60 Hz
(switch selectable on rear panel)
Maximum AC Input:
250VAC
Power Consumption:
160VA Peak
Size (W x D x H)
106 mm x 300 mm x 163 mm
(4.25" x 12" x 6.5")
Weight
4.5 kg (10 lb.)
Operating Temperature:
0 to ≤ 40°C
Storage Environment:
− 40 to +70°C
EMI and Safety:
CE Compliant
27
LFI-4500 ELECTRICAL SPECIFICATIONS
Model Number
Drive Current Output
Output Current Range
Compliance Voltage
Temperature Coefficient
Short Term Stability (1 hr)
Long Term Stability (24 hrs.)
Noise and Ripple (rms)
High Bandwidth Mode
CW Mode Œ
Photodiode Feedback
PDI Range 1 (20 mA max.) •
PDI Range 2
Max. forward PD Bias voltage
Const. Power Output Stability
External Analog Modulation
Input Impedance (0-10 V)
Transfer Function 1
Transfer Function 2
Bandwidth (3 dB) Ž
High Bandwidth
CW Mode Œ
Display
PDI Range 1 •
PDI Range 2
Laser Diode Current
LD Limit Monitor & Limit Setpoint
LD forward voltage
LFI-4502
LFI-4505
LFI-4510
LFI-4532
LFI-4565
0 - 200 mA
> 4.3 V
< 100 ppm/°C
< 20 ppm
< 50 ppm
0 - 500 mA
>4V
< 100 ppm/°C
< 20 ppm
< 50 ppm
0 - 1 Amp
> 3.7 V
< 100 ppm/°C
< 20 ppm
< 50 ppm
0 - 3.25 Amps
> 3.6 V
< 100 ppm/°C
< 20 ppm
< 50 ppm
0 - 6.5 Amps
> 3.3 V
< 100 ppm/°C
< 20 ppm
< 50 ppm
< 5 µA
< 1 µA
< 8 µA
< 1 µA
< 10 µA
< 3 µA
< 15 µA
< 5 µA
< 20 µA
< 5 µA
50 - 2000 µA
15 - 200 µA
0.200 V
< 0.02 %
50 - 2000 µA
15 - 200 µA
0.200 V
< 0.02 %
50 - 2000 µA
15 - 200 µA
0.200 V
< 0.02 %
50 - 2000 µA
15 - 200 µA
0.200 V
< 0.02 %
50 - 2000 µA
15 - 200 µA
0.200 V
< 0.02 %
60 kΩ
40 mA/V
4 mA/V
60 kΩ
100 mA/V
10 mA/V
60 kΩ
200 mA/V
20 mA/V
60 kΩ
650 mA/V
65 mA/V
60 kΩ
1300 mA/V
130 mA/V
DC -200 kHz
DC - 32 Hz
DC - 200 kHz
DC - 32 Hz
DC - 200 kHz
DC - 32 Hz
DC - 200 kHz
DC - 32 Hz
DC - 50 kHz
DC - 32 Hz
0 - 1999 µA
0 - 199.9 µA
0 - 199.9 mA
0 - 199.9 mA
9.99 V max
0 - 1999 µA
0 - 199.9 µA
0 - 500 mA
0 - 500 mA
9.99 V max
0 - 1999 µA
0 - 199.9 µA
0 - 1.000 A
0 - 1.000 A
9.99 V max
0 - 1999 µA
0 - 199.9 µA
0 - 3.25 A
0 - 3.25 A
9.99 V max
0 - 1999 µA
0 - 199.9 µA
0 - 6.50 A
0 - 6.50 A
9.99 V max
ΠMeasured with maximum noise filtering on configuration switch.
• The maximum photodiode range can be increased to 20 mA. Set the unit to the 2000 µA range and place a 10 Ω resistor across pins 5 & 6 on the output connector.
Ž Modulation bandwidth is dependent on limit current setting and output load impedance. Bandwidth specifications are measured at maximum limit current setting and half maximum output current with a laser
diode load. Simulated laser diode loads may produce varied results
28
MECHANICAL SPECIFICATIONS
29
WARRANTY
If you have any questions or comments, please call our technical staff at (406)
587-4910. Our hours are 8:00 a.m. to 5:00 p.m. MT.
Wavelength warrants the LFI 4500 Series laser diode drivers controllers for
one year against defects in materials and workmanship when used within
published specifications. This warranty extends only to purchaser and not to
users of purchaser’s product. If Wavelength receives written notice of such
defects during the warranty period, we will either repair or replace products
which prove to be defective. It is purchaser’s responsibility to determine the
suitability of the products ordered for its own use. Wavelength makes no
warranty concerning the fitness or suitability of its products for a particular use
or purpose; therefore, purchaser should thoroughly test any product and
independently conclude its satisfactory performance in purchaser’s
application. No other warranty exists either expressed or implied, and
consequential damages are specifically excluded. The remedies provided
herein are the Buyer’s sole and exclusive remedies.
All products returned must be accompanied by a Return Material Authorization
(RMA) number obtained from the Customer Service Department. Returned
product will not be accepted for credit or replacement without our permission.
Transportation charges or postage must be prepaid. All returned products
must show invoice number and date and reason for return.
The information contained within this document is subject to change without
notice. Wavelength Electronics makes no warranty of any kind with regard to
this material, including, but not limited to, the implied warranties of
merchantability and fitness for a particular purpose. No part of this document
may be photocopied, reproduced, or translated to another language without
the prior written consent of Wavelength Electronics.
PHONE (406) 587-4910 FAX (406) 587-4911
email: wavelength@imt.net
P O BOX 865, BOZEMAN, MT 59771
31