Laird has developed a platform of customisable thermoelectric assemblies (TEAs) specifically designed for thermal management in small form-factor pluggable (SFP) transceivers. Optical transceivers are used in communication equipment to transmit data at distances up to 1 km away for outdoor applications. Each unit contains a temperature sensitive laser diode, and the ability to transmit data at higher speeds depends on keeping the temperature typically below 70ºC.
The thermoelectric-based ATC (Active Transceiver Cooler) Series removes heat from the optical module to maintain peak performance and minimise loss in packets of information. The ATC line has been optimised to remove heat from three types of transceivers: SFP, XFP and QSFP.
The upcoming deployment of 5G networks, in addition to increased data traffic on established LTE and LTE-Advanced networks, is pushing the demands for higher data rates to ensure quality of service (QoS) for mobile device users. However, faster data communications presents significant thermal challenges for critical components such as optical transceivers.
These devices are installed in outdoor radio units to transmit and receive data from the base station. The temperature of these devices, particularly in outdoor environments, increases due to smaller form factors and no forced airflow, which raises the amount of heat radio units need to dissipate. This results in high temperatures that exceed the maximum operating limit of the optical transceiver that requires an active cooling solution.
"The traditional thermal solution for the SFP is passive, containing an interface material attached to a bulky heat sink that dissipates heat through natural convection. This type of cooling has had difficulty rejecting heat into the ambient environment for radio units in LTE and upcoming 5G systems," said Anders Kottenauer, Senior Vice President of Laird's Engineered Thermal Systems Business.
"Laird's new ATC Series of miniature form factor thermoelectric assemblies provide an innovative way to remove heat from critical optical components that operate in high temperature environments. This improves reliability of data transmission and reduces latency."
The custom ATC Series requires no maintenance and are designed to cool hot spots up to 30 degree C below surrounding environment conditions. The TEAs are optimised to specific footprints and input power constraints that match the SFP, XFP or QSFP transceiver.
Offering a high Coefficient of Performance (COP) without forced airflow, the customisable thermoelectric modules offer a highly reliable thermal solution built to operate in elevated temperatures long term.
Adequate heat sinking is required to keep the hot side temperature down and prevent thermal runaway. Laird’s design employs a proprietary interface material and mounting clips to assemble the TEA onto an EMI cage with an aluminum heat spreader. The thermal solution also uses a high temperature solder and special plating to operate in high temperature environments.