An Energy-Efficient CMOS Line Driver Using Adiabatic Switching

Abstract

The energy recovery principle used in high-efficiency power supplies can be applied to digital CMOS logic to reduce dynamic power dissipation. We describe experiments with a custom line-driver chip and resonant power supply that can switch eight 100pF loads at 1MHz over 6 times more efficiently than conventional CMOS. The paper describes the adiabatic charging principle underlying this class of designs, which allows trading off switching time for increased energy efficiency. We emphasise the importance of including power supply and control logic overhead in evaluations of the net energy savings, and show how this overhead modifies the time-energy trade-off formula. The effect of non-ideal devices is also investigated.