“The reason we stop at 12V is because of the limitations of silicon,” specifically in power MOSFETs, explains Alex Lidow, CEO of Efficient Power Conversion (EPC), a company that specializes in GaN circuitry. “The speed of your device — how fast it can switch — determines how far it can reach in terms of input voltage to output voltage. Because of the much higher switching speeds of gallium nitride you can efficiently go from 48V all the way down to 1V all in one stage.”
EPC supplies Texas Instruments Inc. (NYSE: TXN) with GaN transistors that TI incorporates in its LMG5200 modules designed for 48V to 1V conversion. TI claims its modules operate at 90% to 91% efficiency, Lidow notes.In comparison, the efficiency of multi-stage voltage conversion with silicon MOSFETs maxes out somewhere in the 77% to 78% range. When you go from silicon-based conversion to GaN-based conversion, “you cut your power losses in half, and you improve your server power efficiency by 10% with just that one act,” Lidow says.