Analog Power AMR492N MOSFET Chosen by Akros Silicon July 1 2015 Akros Silicon, a San Jose based IC manufacturer, tested Analog Power MOSFETs versus the competition and found Analog Power AMR492N has the highest efficiency of all the parts tested. New versions of the AS1138 evaluation board use the AMR492N MOSFET. Here is one of their promotion slides: The AMR492N MOSFET is a great choice for 25W PoE designs, especially with ICs that use a 5V gate drive as it has a guaranteed R DS(on) specification at VGS = 4.5V. It is about 1% more efficient than the Fairchild FDMS86242. For 10V+ gate drive designs, AMR494N may be best. Part AMR492N Type Single N VDS Max V 150 VGS Max V 20 RDS(on) m Ohm @ VGS = 10-V 4.5-V 140 160 ID Max A 4.9 QG C PD W 14 5 Package SOIC-8PP The 140 m maximum RDS is perfect for 25W and lower power designs. But Analog Power has many other MOSFETs for different power levels of PoE designs including 200V N- and P-Channel MOSFETs: Some examples are shown below: Part AM3490N AM4392N AMR494N AMR496N AM4470N Type Single N Single N Single N Single N Single N VDS Max V 150 150 150 150 200 VGS Max V 20 20 20 20 20 RDS(on) m Ohm @ VGS = 10-V 4.5-V 700 1200 255 290 160 180 65 75 335 75 ID Max A 1.1 2.9 4.6 7.2 7.2 QG C 7 12.5 12 22 22 PD W 2 3.1 5 5 5 Package TSOP-6 SO-8 SOIC-8PP SOIC-8PP SOIC-8PP