Investigation of Stepwise Charging Circuits for Power-Clock Generation in Adiabatic Logic

The generation of power-clocks in adiabatic integrated circuits is investigated. Specifically, we consider stepwise charging strategies (2, 3, 4, 5, 6, 7, and 8-step) based on tank-capacitor circuits, comparing them in terms of their energy recovery properties and complexity. We show that energy recovery achievable depends on the tank-capacitor size. We also show that tank-capacitor sizes can be reduced as their number increases concluding that combined tank capacitance (CTT) versus load capacitance (CL) ratio is the significant parameter. We propose that using a CTT/CL ratio of 10 and using a 4-step charging power-clock constitute appropriate trade-offs in practical circuits.