High Efficiency Thermoelectric Cooler Controller

The LTC1923 is a pulse width modulator intended for thermoelectric cooler (TEC) or heater applications requiring either unidirectional or bidirectional drive circuits. All of the necessary control circuitry and two sets of complementary output drivers are integrated into the LTC1923 to drive a full bridge, providing an efficient means of bidirectional current flow to the TEC. An accurate temperature control loop to stabilize the temperature of a laser diode system is easily achieved with the addition of just a few external components. Typical temperature setpoint accuracy of 0.1°C is achievable with the LTC1923. Adding an instrumentation amplifier front end allows setpoint stability of 0.01°C.

The part features independent adjustable heating and cooling pulse-by-pulse current limit, current soft-start for controlled start-up, output slew rate control to reduce system noise, differential current sense and voltage amplifiers and a host of auxiliary circuits to protect the laser and provide redundant system monitoring.

Applications

* Laser-Based Fiber Optic Links

* Medical Instruments

* CPU Temperature Regulators

* High Efficiency, Low Noise Topology

* Adjustable Output Slew Rate Reduces EMI

* Full-Bridge Controller for Bidirectional Current Control

* Adjustable Pulse-by-Pulse Bidirectional TEC Current Limit

* Open/Shorted Thermistor Indication

* Solution Footprint in Less Than 0.6" x 0.8"

(Double-Sided PCB)

* Available in 5mm x 5mm QFN and 28-Pin SSOP Packages

* TEC Voltage Clamping

* TEC Current, Voltage and Heat/Cool Status Outputs

* Adjustable/Synchronizable Oscillator Frequency Reduces Filter Component Size and System Noise

* 2.5V Reference Voltage Output

* 2.7V Minimum Operating Voltage