ILX Lightwave LDT-5525 User manual

User’s Guide
Temperature Controller
LDT-5525
ILX Lightwave Corporation P. O.Box 6310 Bozeman, MT, U.S.A. 59771 :· · · 1-800-459-9459 · ·
www.ilxlightwave.com
U.S. & Canada International Inquiries: 406-586-1244 Fax [phone]
E-mail: [email protected]
70019904_7/01

Safety and Warranty Information
! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !
S AFETY AND W ARRANTY I NFORMATION
The Safety and Warranty Information section provides details about cautionary symbols used in the
manual, safety markings used on the instrument, and information about the Warranty including
Customer Service contact information.
Safety Information and the Manual
Throughout this manual, you will see the words Caution and Warning indicating potentially
dangerous or hazardous situations which, if not avoided, could result in death, serious or minor
injury, or damage to the product. Specifically:
!
CAUTION
Caution indicates a potentially hazardous situation which can result in minor or
moderate injury or damage to the product or equipment.
WARNING
Warning indicates a potentially dangerous situation which can result in serious injury or
death.
WARNING
Visible and/or invisible laser radiation. Avoid direct exposure to the beam.
General Safety Considerations
If any of the following conditions exist, or are even suspected, do not use the instrument until safe
operation can be verified by trained service personnel:
•Visible damage
•Severe transport stress
•Prolonged storage under adverse conditions
•Failure to perform intended measurements or functions
If necessary, return the instrument to ILX Lightwave, or authorized local ILX Lightwave distributor,
for service or repair to ensure that safety features are maintained.
All instruments returned to ILX Lightwave are required to have a Return Authorization Number
assigned by an official representative of ILX Lightwave Corporation.

Safety and Warranty Information
S AFETY S YMBOLS
This section describes the safety symbols and classifications.
Technical specifications including electrical ratings and weight are included within the manual. See
the Table of Contents to locate the specifications and other product information. The following
classifications are standard across all ILX Lightwave products:
•Indoor use only
•Ordinary Protection: This product is NOT protected against the harmful ingress of moisture.
•Class I Equipment (grounded type)
•Mains supply voltage fluctuations are not to exceed ±10% of the nominal supply voltage.
•Pollution Degree II
•Installation (overvoltage) Category II for transient overvoltages
•Maximum Relative Humidity: <80% RH, non−condensing
•Operating temperature range of 0 °C to 40 °C
•Storage and transportation temperature of ˘40 °C to 70 °C
•Maximum altitude: 3000 m (9843 ft)
•This equipment is suitable for continuous operation.
Safety Marking Symbols
This section provides a description of the safety marking symbols that appear on the instrument.
These symbols provide information about potentially dangerous situations which can result in death,
injury, or damage to the instrument and other components.
Caution,
refer to
manual
Earth
ground
Terminal
Alternating
current
Visible and/or
invisible laser
radiation
Caution, risk
of electric
shock
Protective
Conductor
Terminal
Caution, hot
surface
Frame or
chassis
Terminal
On: In position of a bistable push control. The
slash (I) only denotes that mains are on.
Off: Out position of a bistable push control.
The circle (O) only denotes that mains are off.
or
(I) or
(O)

Safety and Warranty Information
W ARRANTY
ILX LIGHTWAVE CORPORATION warrants this instrument to be free from defects in material and
workmanship for a period of one year from date of shipment. During the warranty period, ILX will
repair or replace the unit, at our option, without charge.
Limitations
This warranty does not apply to fuses, lamps, defects caused by abuse, modifications, or to use of
the product for which it was not intended.
This warranty is in lieu of all other warranties, expressed or implied, including any implied warranty
of merchantability or fitness for any particular purpose. ILX Lightwave Corporation shall not be liable
for any incidental, special, or consequential damages.
If a problem occurs, please contact ILX Lightwave Corporation with the instrument’s serial number,
and thoroughly describe the nature of the problem.
Returning an Instrument
If an instrument is to be shipped to ILX Lightwave for repair or service, be sure to:
1Obtain a Return Authorization number (RA) from ILX Customer Service.
2Attach a tag to the instrument identifying the owner and indicating the required service or
repair. Include the instrument serial number from the rear panel of the instrument.
3Attach the anti−static protective caps that were shipped with the instrument and place the
instrument in a protective anti−static bag.
4Place the instrument in the original packing container with at least 3 inches (7. 5 cm) of
compressible packaging material. Shipping damage is not covered by this warranty.
5Secure the packing box with fiber reinforced strapping tape or metal bands.
6Send the instrument, transportation pre−paid, to ILX Lightwave. Clearly write the return
authorization number on the outside of the box and on the shipping paperwork. ILX
Lightwave recommends you insure the shipment.
If the original shipping container is not available, place your instrument in a container with at least 3
inches (7.5 cm) of compressible packaging material on all sides.
Repairs are made and the instrument returned transportation pre−paid. Repairs are warranted for the
remainder of the original warranty or for 90 days, whichever is greater.
Claims for Shipping Damage
When you receive the instrument, inspect it immediately for any damage or shortages on the
packing list. If the instrument is damaged, file a claim with the carrier. The factory will supply you
with a quotation for estimated costs of repair. You must negotiate and settle with the carrier for the
amount of damage.

Safety and Warranty Information
Comments, Suggestions, and Problems
To ensure that you get the most out of your ILX Lightwave product, we ask that you direct any
product operation or service related questions or comments to ILX Lightwave Customer Support.
You may contact us in whatever way is most convenient:
Phone . . . . . . . . . . . . . . . . . . . . . . . . . . . (800) 459−9459 or (406) 586−1244
Fax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (406) 586−9405
Email. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [e-mail]
Or mail to:
ILX Lightwave Corporation
P. O. Box 6310
Bozeman, Montana, U.S.A 59771
www.ilxlightwave.com
When you contact us, please have the following information:
If ILX Lightwave determines that a return to the factory is necessary, you are issued a Return
Authorization (RA) number. Please mark this number on the outside of the shipping box.
You or your shipping service are responsible for any shipping damage when returning the
instrument to ILX Lightwave; ILX recommends you insure the shipment. If the original shipping
container is not available, place your instrument in a container with at least 3 inches (7.5cm) of
compressible packaging material on all sides.
We look forward to serving you even better in the future!
Model Number:
Serial Number:
End−user Name:
Company:
Phone:
Fax:
Description or sketch of what
is connected to the ILX
Lightwave instrument:
Description of the problem:

i
Table of Contents
Chapter 1 - GENERAL INFORMATION..............................................................................................................1
1.1 Introduction 1
1.2 Your Comments................................................................................................................................................1
1.3 Product Overview............................................................................................................................................1
1.4 Available Options and Accessories .............................................................................................................2
1.5 Specifications...................................................................................................................................................3
Chapter 2 - OPERATION.......................................................................................................................................1
2.1 Introduction ...................................................................................................................................................1
2.2 Installation ...................................................................................................................................................2
2.2.1 AC Power Considerations...........................................................................................................................2
2.2.2 Rack Mounting..............................................................................................................................................3
2.3 Power-Up Sequence........................................................................................................................................3
2.4 Introduction to the LDT-5525 Front Panel...................................................................................................3
2.4.1 Adjustments ..................................................................................................................................................4
2.4.2 Display ...................................................................................................................................................4
2.4.3 Parameters ...................................................................................................................................................5
2.4.4 Parameter Setup.............................................................................................................................................6
2.4.5 SENSOR CAL................................................................................................................................................6
2.4.6 Output ...................................................................................................................................................7
2.4.7 Control Mode................................................................................................................................................9
2.4.8 Error Indicators..............................................................................................................................................9
2.4.9 Analog Output..............................................................................................................................................9
2.4.7 Control Mode..............................................................................................................................................10
2.4.8 Error Indicators............................................................................................................................................10
2.4.9 Analog Output............................................................................................................................................10
2.5 Back Panel Controls and Connections.......................................................................................................11
2.5.1 SENSOR SELECT Switch...........................................................................................................................12
2.5.2 TEC Connector............................................................................................................................................13
2.5.3 TEC Grounding Considerations................................................................................................................13
2.6 General Operating Procedures .....................................................................................................................14
2.6.1 Warm-Up and Environmental Considerations........................................................................................14
2.6.2 Temperature Mode Operation...................................................................................................................14
2.6.3 Resistance Mode Operation......................................................................................................................15
2.6.4 External Safety Switch Operation.............................................................................................................17
2.6.5 Booster Operation.......................................................................................................................................17
Chapter 3 - MAINTENANCE AND TROUBLESHOOTING.............................................................................1
3.1 Introduction ...................................................................................................................................................1
3.2 Calibration Overview.......................................................................................................................................2
3.2.1 Recommended Equipment...........................................................................................................................2
3.2.2 Environmental Conditions...........................................................................................................................3
3.2.3 Warm-Up ...................................................................................................................................................3
3.3 Calibration Adjustments.................................................................................................................................3
3.3.1 Thermistor Calibration..................................................................................................................................3
3.3.2 AD590 Sensor Calibration...........................................................................................................................5
3.3.3 LM335 Sensor Calibration...........................................................................................................................6
3.3.4 ITE Current Calibration................................................................................................................................6
3.3.5 Troubleshooting...........................................................................................................................................7
5525 Production Calibration Procedure .............................................................................................................10
Appendix A - The Steinhart-Hart Equation
Appendix B - Sensing Current and Thermistor Selection
Appendix C - AD590 amd LM335 Sensor Calibration

1-1
Chapter 1
GENERAL INFORMATION
1.1 Introduction
This manual contains operation and maintenance information for the LDT-5525 Temperature Controller. If you want
to get started right away, read Chapter 2, which covers Operation, first.
1.2 Your Comments
Our goal is to make the best laser diode instrumentation available anywhere. To achieve this, we need your ideas and
comments on ways we can improve our products. We invite you to contact us at any time with your suggestions.
(Please see the third cover page.)
1.3 Product Overview
The LDT-5525 Temperature Controller is a microprocessor-based, precision thermoelectric temperature controller
designed for temperature control of laser diodes, detectors and other temperature sensitive devices. The LDT-5525
can be used for laser diode testing, laser diode frequency stabilization, IR detector cooling, and to determine the
characteristics of electronic devices. The LDT-5525 combines high analog stability with the versatility of a
microprocessor-based instrument. The internal microprocessor controls the operation of the LDT-5525 and performs
the non-linear conversion of thermistor resistance to temperature based on two user-defined constants.
You can configure the LDT-5525 to operate with a wide variety of thermistor temperature sensors and TE modules, as
well as AD590 series and LM335 series temperature sensors.

1-2
Features of the LDT-5525 include:
•Intuitive front panel layout
•Large and easy-to-read green LED display
•Display resolution of 0.1 degree Centigrade
•Output current limit control to safely operate all TE coolers
•Configurable for a variety of thermal sensors
•Output will supply 4 amps, 24 Watts
•Closed-case calibration
1.4 Available Options and Accessories
Options and accessories available for the LDT-5525 Temperature Controller include the following:
DESCRIPTION MODEL
NUMBER
Single Rack mount kit 134
(enables installation into a standard 19 inch rack)
Dual Rack mount kit
(enables installation of two LDT-5525 instruments
into a standard 19 inch rack)
135
Temperature Controlled Laser Diode Mount 4407
Temperature Controlled Laser Diode Mount
(available with collimating assembly) 4412
High Power Laser Diode Mount 4442
Temperature Controller Interconnect Cable
(unterminated)
Calibrated 10 Kohm Thermistor
Uncalibrated 10 Kohm Thermistor
Uncalibrated AD590LH IC Temperature Sensor
Uncalibrated LM335 IC Temperature Sensor
501
510
520
530
540
Other Laser Diode Mounts are available. Please contact ILX Lightwave for information on additional options for your
applications.

1-3
1.5 Specifications
Output1
Output Type:
Control Algorithm: Bipolar constant current source Smart Integrator, Hybrid PI
Compliance Voltage: 6 volts at 4 Amps
Maximum Current Output: 4 Amps
Maximum Output Power:224 Watts, typical
Current Limit Control Range: 0 to 4.4 Amps
Current Limit Accuracy: ±50 mA
Ripple/Noise:3<1 mA
Temperature Control
Temperature Range:4
Sensor Type:
Thermistor Sensing Current:
Temperature Set Point
Resolution:
Short Term Stability:5
Long Term Stability:
-99 to 199.9°C
-20 to +70°C with typical (NTC) 10K
thermistor
2-wire thermistor, LM335 voltage type, or
AD590 current type
10 µA or 100 µA
0.1°C
±0.005°C
±0.01°C
____________________________________________________________
1Output current and power are rated into a 1 ohm load
2Higher output powers can be accommodated by using an external booster. Contact ILX Lightwave for further information.
3Broadband noise (10 Hz to 10 MHz) is measured at 1 Amp output current.
4Temperature control range depends primarily on the type of thermistor and TE module used. The range can be extended higher or
lower by selecting appropriate components. See Appendix B for more details.
5Short term temperature stability is a strong function of the thermal environment of the thermistor and TE module. Room air
currents in particular can easily cause fluctuations of 0.1°C in an exposed mounting configuration.

1-4
LDT-5525 Specifications (continued)
Thermistor range (10 µA):
Thermistor range (100 µA):
Usable Thermistor Range:
Thermistor Resistance
Resolution (10 µA):
Thermistor Resistance
Resolution (100 µA):
Thermistor Resistance
Accuracy:
AD590 Reverse Bias:
LM335 Bias:
User Calibration:
Thermistor:
IC sensor:
0.0 to 450.0 KΩ
0.00 to 45.00 KΩ
25 to 450,000 Ω, typical
0.1 KΩ
0.01 KΩ
±0.05 % of FS
8 Volts
0.6 mA
Steinhart-Hart equation (2 constants)
2-point
Measurement (Display)
Display type:
TE Current Range:
TE Current Resolution:
TE Current Accuracy:
Temperature Range:
Temperature Resolution:
Temperature Accuracy6:
0°C:
20°C:
4-digit LED
-4.00 to 4.00 Amps
0.01 Amps
±0.03 Amps
-99.9 to 999.9°C
0.1°C
±0.6°C, typical
±0.3°C, typical
30°C: ±0.4°C, typical
50°C: ±0.6°C, typical
____________________________________________________________
6Accuracy figures quoted are typical for a calibrated 10K thermistor. Accuracy figures are relative to calibration standard and are
dependent on the user-defined configuration of the instrument. Variation from typical value is largely due to uncertainty in
thermistor calibration.

1-5
LDT-5525 Specifications (continued)
General
Output Connectors:
TEC I/O:
Analog Output:
Power Requirements:
Size:
Weight:
Ambient Temperature Range:
Humidity:
Warm-up:
15-pin , D-sub
BNC
90 - 125, 210 - 250 VAC (jumper
selectable), @ 50-60 Hz
3.5" x 7.3" x 12"
8.0 lbs.
Operating: 0 to 40°C
Storage: -40 to 70°C
<85%, rel., non-condensing
1 hour to rated accuracy

2-1
Chapter 2
OPERATION
2.1 Introduction
This chapter describes how to install, adjust, and operate the LDT-5525 Temperature Controller. It is divided into
sections covering installation, familiarization and adjustment, and normal operating procedures.
Section 2.4 gives an overview of the LDT-5525's front panel features, and it presents a guide to quickly familiarize the
user with the front panel operations.
2.2 Installation
Installation procedures and considerations are covered in Sections 2.2.1 - 2.2.2.
2.2.1 AC Power Considerations
The LDT-5525 Series Controllers can be configured to operate at nominal line voltages of 100, 120 220, 230-240 VAC
(all ±10%). This is done at the factory and need not be changed before operating the instrument. However, check to
be sure that the voltage printed on the back panel of the instrument matches the power-line voltage in your area.
WARNING
To avoid electrical shock hazard, connect the instrument to properly earth-grounded,
3-prong receptacles only. Failure to observe this
precaution can result in severe injury or death.

2-2
2.2.2 Rack Mounting
The LDT-5525 Series Precision Temperature Controller may be rack mounted by installing a rack mount flange on
either side of the enclosure. All rack mount accessory kits contain detailed mounting instructions. Refer to Section
1.3 for applicable rack mount accessory part numbers.
2.3 Power-Up Sequence
With the LDT-5525 Series Precision Temperature Controller connected to an AC power source, pressing the POWER
switch will supply power to the instrument and start the power-up sequence.
During the power-up sequence, the following takes place. For about two seconds all indicators light up, and all of the
7-segment displays indicate "8". Then all lamps are turned off for two seconds. Then, the sensor switch position is
displayed for two seconds. After this, the unit is configured to the state it was in when the power was last shut off
(except for the display mode which defaults to I TE measurement). The adjust knob is always disabled at power up.
2.4 Introduction to the LDT-5525 Front Panel
The LDT-5525 Temperature Controller's front panel contains displays and controls for the Temperature Controller
hardware. Each of the labeled areas on the front panel (i.e. DISPLAY or MODE) is described in this chapter.
Refer to Figure 2.1 for the following discussions of the LDT-5525 Temperature Controller front panel sections. The
key words are in capital letters for quick identification.

2-3
Error Parameter Display Adjust Adjust
Indicators Switch Switch Enable Knob
Switch
Ω
Ω
Ω
AC POWER Analog CAL Mode Output
ON/Off Output Select Select On/Off
Switch Connector Switch Switch Switch
Figure 2.1 LDT-5525 Front Panel
2.4.1 Adjustments
The ADJUST section contains the Adjust knob for entering values, and it contains the ENBL (adjust enable) switch
and indicator. In order to make any adjustment, the ENBL indicator must be lit. Pressing the ENBL switch toggles the
ENBL indicator on or off.
2.4.2 Display
The display is used to show measurements, output set point, and parameter set points. Whenever a set point is being
displayed, the VIEW SET indicator will be lit.

2-4
The DISPLAY switch is used to select the measured current (I TE), temperature, resistance, or the set point value.
The set point type is determined by the MODE selection. Repeatedly pressing the DISPLAY switch will cycle the
display from ITE to temperature to resistance (with thermistor sensors only) to set point and back to ITE, and so on.
When in I TE mode, the set point will be TE current.
When in R mode, the set point will be thermistor resistance in KΩ. R mode is not available if the back panel SENSOR
SELECT switch is set to LM335 or AD590. R mode operation may offer improved set point resolution (over T mode),
depending on the desired temperature set point. See Section 2.6.3 for R mode operation.
NOTE: The resistance set point is NOT maintained if the control mode is changed (e. g. from R mode to T mode).
Also, if the SENSOR SELECT switch is moved from 10 µA to 100 µA while in R mode, the resistance set point will be
rounded to match the display resolution.
When in T mode the set point will be temperature in°C. See Section 2.6.2 for T mode operation.
When the output is off and a measurement is displayed, if the adjust knob is turned the control mode set point will be
displayed for three seconds. If the set point is adjusted (by turning the adjust knob) the set point timer will be
restarted. Therefore, three seconds after the set point is adjusted the display will return to the last measurement.
2.4.3 Parameters
The LDT-5525 Temperature Controller allows adjustment of the following parameters, I LIMIT (TE current limit), T
LIMIT (temperature limit) and GAIN (sensor feedback amplifier gain). In addition, the sensor calibration values may
be entered (see section 2.4.5, CAL).
The LDT-5525 will limit the I TE output to the I LIMIT value, regardless of the set point or control mode.

2-5
The temperature is limited (via the sensor feedback) to the T LIMIT value. If the sensor reads a temperature which is
greater than T LIMIT, the I TE output will be shut off.
The GAIN value is used to control the sensor feedback gain, and thus the temperature settling time and overshoot. If
the GAIN is set too low (1 is the lowest setting) the TE cooler will take longer to reach the temperature set point. If
the GAIN is set too high (300 is the highest setting) the actual temperature may oscillate around the set temperature.
The optimum GAIN setting depends on the type of TE cooler and temperature that you are setting . Set the GAIN to
its lowest value and then try increasing it until the temperature oscillates around the set temperature. Then, reduce
the GAIN one step.
2.4.4 Parameter Setup
The PARAMETER switch is used to view and edit the parameters. Repeatedly pressing the PARAMETER switch will
cycle through the parameters.
When a parameter is selected for viewing, its value will remain on the display for three seconds. If an adjustment is
made to the parameter (by turning the adjust knob) the three second timer will be restarted. Three seconds after the
parameter adjustment is done, the display will revert to the last measurement mode.
2.4.5 SENSOR CAL
These are the constants of the Steinhart-Hart equation that the user enters to calibrate the TEC for different
thermistors' temperature conversions. The Steinhart-Hart equation is used to derive temperature from the non-linear
resistance of an NTC (Negative Temperature Coefficient) thermistor. For information on setting C1 and C2 for
thermistors, see Appendix A. For information on thermistor selection and sensor current selection, see Appendix B.

2-6
When a linear sensor device (such as an AD590 or LM335) is used, a linear equation is used. If a linear sensor’s
calibration is not known, set C1 = 0.00, C2 = 1.00. For more information on linear sensor calibration, see AppendixC.
The range of values for C1 and C2 are -9.99 to +9.99.
To read C1 or C2, press the CAL button until it sequences to the desired constant. The C1 or C2 indicator will become
lit to indicate which constant is selected. To change the value, turn the ADJUST knob until the correct value is
displayed.
Appendix A contains an explanation of the Steinhart-Hart equation and a computer program to determine these
values for any thermistor.
Appendix C contains information on sensor calibration constants for AD590 and LM335 sensors. Since these devices
are used over their linear range, the constants C1 and C2 are used in this case to determine a linear approximation of
the temperature, rather than the Steinhart-Hart non-linear approximation which applies for thermistors. The
appropriate algorithms are automatically implemented whenever the sensor type is selected via the back panel
SENSOR SELECT switch. However, C1 and C2 must be changed by the user.
2.4.6 Output
The OUTPUT section contains the ON switch and indicator. The ON indicator is lit whenever the output is on.
Pressing the ON switch will toggle the TEC current output on or off.
Conditions Which Will Automatically Shut Off the OUTPUT
1. Temperature Limit
2. External (Temp Limit) Safety Switch is closed (see Section 2.6.3)
3. Booster Changed (While Output On), (see Section 2.6.4)
4. Sensor Open (While Output On)
5. TEC Module Open (While Output On)
6. SENSOR SELECT Switch Moved (While Output On)