Integrated MOSFET

International Rectifier has introduced the IRF4000, a 100 V-rated device integrating four HEXFET MOSFETs into a single power MLP package for power-over-ethernet applications.

The device complies to the IEEE 802.3af specification for networking and communications infrastructure systems, such as ethernet switches, routers and hubs, delivering up to 15 W per port, replacing four individual SOT-223-packaged MOSFETs.

The reduced footprint equates to a space savings of up to 80%, or 19 cm2, of circuit board area in a typical 48-port board.

The MOSFET operates like a hot-swap FET, transferring power from the PSE to the PD, and must operate in the linear region through a demanding worst-case operating condition therefore requiring an extremely robust safe operating area.

The low transconductance silicon technology used in the device combines with about 1°C/W package thermal resistance to enable efficient removal of heat while operating in the linear region and has been fully electrically and thermally characterised under worst case IEEE 802.3af operating conditions.

The device guarantees a 56% higher device safe operating area compared with individual SOT-223 MOSFETs.

In addition to 48-port systems, the device is suitable for 96-port applications or for smaller PoE 'jack companion' modules using 12 ports where four ports can be addressed with a single IRF4000 device. The device is qualified to industrial moisture sensitivity level (MSL) 3.

The IRF4000 is compliant with the upcoming PoE Plus architecture for high power loads.