Diodes New 100V MOSFET optimizes Power over Ethernet applications

     Diodes Incorporated's new DMN10H120SFG MOSFETs serve as switches for IEEE 802.3-compliant 48V Power over Ethernet (PoE) systems. The ability to power end applications such as wireless access points, VoIP voip, point-of-sale terminals, calling systems, IP network surveillance lenses, and building management devices via Ethernet cables.

     In power supply devices such as LAN routers and mid-span devices, 100V N-channel MOSFETs connect the power supply to Class 5 or Class 6 network cables. The cable then reduces costs by eliminating the power supply within the terminal device and provides power and data. The device also protects the end user because Ethernet cable power is available in the 44V to 57V application range and complies with the safety Ultra Low Voltage (SELV) rating of 60V, eliminating the need for strict end-device isolation and certification, and simplifying system maintenance. The device operates at these voltages to minimize I2R losses, helping to increase the power supply to the end device and improve efficiency.

     The DMN10H120SFG MOSFETs provide ample headroom for 48V power over Ethernet with a 100V BVDSS rating. It also extends the Safe Working area (SOA) to withstand power dissipated by a short circuit failure, such as a broken Ethernet cable, until the power supply device controller detects the fault and shuts down. The MOSFETs operate in linear mode in this fault state and need to dissipate 30W of power for at least 20 milliseconds, even at operating temperatures up to +60°C.

     The DMN10H120SFG comes in a space-saving PowerDI3333 package. Diodes also offers SOT23, SOT223 and TO252 (DPAK) package options for a wide range of 100V DMN10H series. The avalanche resistant DMN10H099SK3 in the TO252 package, for example, is fully unclamped inductive switch tested to ensure that it can withstand energy pulses at switching inductive loads such as coils, motors and relays.