Active bridge technology for Ethernet-based IoT devices

The first member of Fairchild’s next-generation GreenBridge active bridge quad MOSFET technology has been launched. The FDMQ8205 is said to suit Power Over Ethernet applications (POE), such as security cameras, wireless access points, LED lighting and other powered devices.

GreenBridge technology is compliant with the IEEE 802.3at standard and is claimed to have up to 10 times lower power dissipation than Schottky diodes. The thermal performance allows designers to reduce or eliminate heat sinks to simplify their product design, decrease BOM costs and shrink PCB size.

“Dealing with heat has always been a critical design challenge, but even more so with these new generations of IoT devices that require 25.5W or more. The leading edge MOSFET technology in our latest GreenBridge devices help designers eliminate excessive heat and achieve key system design goals, including higher efficiency, ensuring standards compliance and decreasing overall size and reducing costs,” said Suman Narayan, vice president of the intelligent power FET division at Fairchild.

The low conduction losses of the next-generation series are another important advantage as power and voltage must be maximized for the limited input power of POE systems. According to Fairchild, the series has 47% lower conduction losses compared to its closest competitor due to the power conversion efficiency of its PowerTrench MOSFET technology.

At just 4.5 x 5mm, the GreenBridge devices incorporate four MOSFETs in an MLP package connected in a full bridge. The devices do not require an external driver, saving additional PCB space.

Other benefits include lower operating temperature, increased efficiency and smaller solution size.