An Efficient Fast Switching Procedure for Stepwise Capacitor Chargers

A new low-power switching procedure for stepwise capacitor chargers is presented. In this procedure, a novel displacement method is utilized to improve the speed by a factor of two while preserving energy efficiency. Moreover, the load capacitor retains its charge after the charging process finishes and permits the circuit charge another predischarged load capacitor without an efficiency degradation problem (instability). Also, the control circuit of the switching procedure is implemented using only flip-flops with no combinational logic, therefore, it systematically prevents glitch power dissipation and improves the efficiency. Analytical derivations are proposed to model the switching procedure and they are verified using MATLAB simulations. Postlayout simulations in 0.18 μm technology and a fabricated PCB using off-the-shelf components prove the analytical derivations and the benefits of the proposed switching procedure.