Diodes Incorporated's new DMN10H120SFG MOSFET is designed to be used as a switch for IEEE 802.3-compliant 48V Power over Ethernet (PoE) systems. The switch can power end applications such as wireless access points, VoIP phones, point-of-sale terminals, calling systems, IP security cameras and building management equipment via Ethernet cables.
In LAN routers and mid-span power supplies, this 100V N-channel MOSFET switches power to a CAT5 (or CAT6) network cable. The cable then provides both power and data, reducing system costs by eliminating power in the end device. Since PoE works between 44V and 57V and can meet 60V safety extra-low voltage (SELV) ratings, it can also protect end users, eliminating the need for strict isolation and terminal equipment certification, while also simplifying system maintenance . When operating at these voltage levels, I2R losses can be minimized, which helps maximize power output to the end device and improves efficiency.
The DMN10H120SFG MOSFET has a 100V BVDSS rating, which provides sufficient headroom for 48V PoE operation. The DMN10H120SFG also provides an extended safe operating area (SOA) that can withstand power consumption due to short-circuit fault conditions (such as a broken Ethernet cable) until the PSE controller detects a fault and shuts down. In this fault condition, the MOSFET enters the linear mode and needs to dissipate 30W for at least 20ms, even if the operating temperature + 60C increases.
DMN10H120SFG is available in a space-saving PowerDI3333 package. In its extensive 100V DMN10H series, the company also offers SOT23, SOT223 and TO252 (DPAK) packages. The company says, for example, the avalanche-reinforced DMN10H099SK3 in TO252 is 100% unclamped inductive switch (UIS) tested to ensure that it can withstand the energy pulses in switching inductive loads such as coils, motors and relays.
