Stacked FETs enable high-efficiency, high-density solutions

High-efficiency, high-density power supplies have been a trend for communications equipment due to increasing power consumption and reduced board space. A stacked-FET switch enables high-efficiency and high-density solutions. Two real design examples are examined to illustrate this point. The first is a 30-A design where the benefits of a stacked-FET switch are evaluated relative to size reduction, efficiency gain and thermal budget savings. A second design implements the stacked-FET switch with an integrated driver to further increase system efficiency in a 60-A supply.

As modern electronics equipment advances in speed and performance, the number of power rails keeps increasing in addition to an increase in power consumption. Conversely, the physical area for power supplies keeps shrinking because precious real estate is given to the core ASIC and processors. As such, a high-efficiency, high-density power supply is a challenge for every power designer.