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Temperature Controller, Thermoelectric, ±5A, ±12V, 60W, GPIB & RS232
4 Weeks
4 Weeks
Temperature Controller, Thermoelectric, ±10A, ±12V, 120W, GPIB & RS232



Advanced Feature Set

LDT-5900 controllers provide the finest balance of features for today’s temperature control needs in laser diode and component testing. In addition to wide temperature control range and uncompromising stability, these instruments combine a fully digital PID feedback loop with a precision 24-bit measurement system for the utmost capability in temperature control and measurement. Control and display temperature from -50°C to 250°C while delivering a low-noise, bipolar current (up to 10A) to the thermo-electric module. This unique temperature control topology offers fast settling time and temperature stability better than 0.005°C - ideal for laser diode applications requiring highly stable wavelength and optical power. Additional features like four-wire voltage and sensor measurements and an AC resistance measurement make these instruments perfect for characterizing TE modules during laser module development, testing, or assembly. Input and output triggers, standard GPIB control, and an auto-tune algorithm all work to accelerate and simplify test automation.

More Power for Faster Temperature Settling

The LDT-5980 provides 120W of output power for production applications that require fast temperature swings over a wide temperature range. The LDT-5980 , with its high voltage and current output, is designed specifically to drive the TECs used in these applications. Temperature setpoint resolution of 0.001°C gives you the ability to control to the exact temperature your application requires, and the PID control loop minimizes overshoot resulting in faster temperature settling times.

Uncompromising Thermal Stability

The LDT-5900 Series lets you easily control the temperature of your laser diode in one of four modes: (1) Constant Temperature (2) Constant Sensor (3) Constant Current or (4) Constant Voltage. Temperature stabilities of 0.005°C ensure device performance and highly reliable test measurements. With 0.005°C stability the LDT-5900 Series are ideal for R&D applications, eliminating mode hopping and significantly reducing RMS noise.

Auto-tune Function Saves You Effort

PID control loops provide unequaled temperature settling and stability performance but can be difficult and time consuming to optimize. Our new auto-tune function saves you effort by automatically determining PID control constants for your particular thermal load. If you change the load, you simply run the auto-tune again and let the LDT-5900 Series do the work of calculating the new control constants.

A Choice of Sensors for Your Application

In addition to a broad range of thermistors and RTDs, the LDT-5900 Series can accommodate IC temperature sensors for control feedback. By using the appropriate equation for the selected temperature sensor and the applicable calibration constants, residual errors of less than 0.005°C can be realized over wide temperature ranges. Sensor constants are easily entered via the front panel or GPIB.

Control and Measurement for Complex Testing

In addition to precision temperature control, the LDT-5900 Series provides four-wire voltage and sensor measurement for the most accurate characterization of laser diode module power consumption and reliable measurements. Independent heating and cooling current limits help achieve the fastest settling times, while protecting your device under all instrument modes. If your application requires checking the integrity of the TE device before and after installation into a module or device, there is no need for a separate instrument. The LDT-5900 Series provides an AC resistance measurement mode that outputs a low level AC current to the device under test and calculates its corresponding resistance.

Automated Temperature Control for Functional Test Systems

These LDT-5900 Series come standard with a high speed GPIB remote interface as well as RS-232 serial communication capability. For quick instrument response without a command program, a TTL trigger-in function steps the instrument through a preprogrammed series of temperature setpoints. A trigger-out signal indicates when the set point has been reached.

Maintain Laser Diode Threshold Current and Wavelength

The above figure figure shows that the threshold current and differential responsivity of a laser diode are strongly affected by the laser’s temperature. The laser threshold will increase exponentially with temperature as exp(T/T0), where T is the laser temperature and T0 is the “characteristic temperature” of the laser (typically between 60 to 150°C). T0 is a measure of the temperature sensitivity of the device with higher values implying that the device is more thermally stable. T0 is an important laser diode characteristic and is commonly extracted from multiple L-I curves. Changes in temperature also affect the bandgap of the semiconductor junction and therefore, the peak wavelength of the gain profile. This results in a linear relationship between temperature and the center wavelength of the laser diode (see above figure) with typical temperature tuning coefficients of 0.3 nm/°C. As a result, a temperature controller plays a key role in determining the laser wavelength. Please see Fundamentals of Laser Diode Control for additional information.