The TEC driver reference design utilises a buck-boost converter and a microcontroller to ensure precise temperature control for sensitive applications.
Many electronic components, including laser diodes in optical modules, require precise temperature regulation to optimise performance and extend operating life. Even a slight 1°C change can cause a 0.1 nm drift in the wavelength of a laser, making temperature control down to 0.1°C critical. Thermoelectric cooling (TEC) devices, which utilise the Peltier effect, offer a solution for such precision. The direction of the current through a TEC determines whether it heats or cools. TIDA-050017, TEC driver reference design for 3.3V inputs from Texas Instruments (TI), uses a TPS63802 low quiescent current buck-boost converter in conjunction with an MSP430FR2433 microcontroller to accurately control the temperature in sensitive applications.
The applications of precise temperature control extend to various domains, including the temperature regulation of laser diodes used in optical modules, long-haul submarine communications, and metro data centre interconnects. Additionally, this technology is crucial for maintaining the optimal operating temperature of lasers and electronics packaging, ensuring their efficient and reliable performance.
The system’s features include low solution costs and a compact power stage, buck-boost converter, that occupies less than 30 mm². This power stage is also notable for its low quiescent current of just 11 μA. Additionally, the system utilises digital PI control to achieve precise temperature regulation, maintaining control within a remarkable 0.1°C. These features collectively ensure efficient and cost-effective operation.
The low quiescent current buck-boost converter is a versatile, high-efficiency, high-output current (2 A) buck-boost converter housed in a compact 3 mm × 2 mm QFN package. It efficiently handles transitions between buck, buck-boost, and boost modes without undesired toggling. In the reference design, the buck-boost converter operates off a 3.3 V regulated voltage rail. It interfaces with the TEC element between the VIN and VOUT pins, adjusting the output voltage from 1.8 V to 5 V.
The design features an integrated Power Save (PFM) mode that enhances efficiency by pausing the switching action at low-load currents. This mode is particularly beneficial when the input voltage (VI) is less than the output voltage (VO), optimising efficiency under these conditions. Conversely, when VI exceeds VO, the device employs the forced Pulse Width Modulation (PWM) mode, which involves continuous switching. This adjustment is necessary as VO may be externally charged above its target value by VI through the TEC element.
TI have tested this reference design. It comes with a bill of materials (BOM), schematics, an assembly drawing, a gerber file, etc. You can find additional data about the reference design on the company’s website. To read more about this reference design, click here.
