Thermoelectric cooler control circuit

摘要

A thermoelectric cooler (TEC) is used to maintain an electronic component, for example, a laser diode, at a set temperature. A thermistor senses the temperature of the laser and through a first control loop causes current to be passed through the TEC so as to adjust the laser temperature. As the temperature of the hot side of the TEC increases above the temperature of the cold side of the TEC, the TEC's cooling efficiency gradually decreases. This is compensated for by adding a second control loop which senses the TEC current and provides an additional gain proportional to the TEC current in the cooling sense. This additional gain is added to the gain provided by the first control loop. The result is a stable, highly responsive temperature controller at all points of the TEC operating range.