N2power_1001-AFeaturing a 3- by 5.3-in. footprint, the 330-W, 1.35-in.-high, open-frame XL330-54 ac-dc power supply delivers a power density of 15 W/in.3 with only 13-CFM cooling. It save 32% more space versus typical 1U units of similar rating (most of which have a 6- by 4-in. footprint), according to developer N2Power. The company also claims that maximum full-load efficiency of 90%, achieved through synchronous rectification, Or-ing MOSFETs, and an active power-factor-correction design, translates into 23% less heat than most comparable power supplies. There are two primary outputs (54 V/1.6 A and 12 V/9 A) and an auxiliary output (12 V/1 A). The 54-V output is 2250 V dc isolated from the other output, making it compatible with Power over Ethernet. Active current sharing is possible on the 54-V output for up to four power supplies operated in parallel. Other features include universal ac input (90 to 264 V ac) and active inrush current protection of 10.5 A at 240 V ac.