Application of GaAs pHEMT technology for efficient high-frequency switching regulators

The potential of GaAs pHEMT technology for low-voltage high-frequency power switching applications is discussed with a view towards their application for power supplies in portable electronic systems. The design and implementation of a 4.5V-to-3.3V buck converter power IC utilizing an enhancement mode pHEMT high side switch is demonstrated. The fabricated buck circuit is capable of operating at switching frequencies ranging from 100-MHz. While operating from a 4.5V supply a power efficiency of 87% is obtained at 100MHz when the output voltage is 3.3V and current is 500mA.