Design of a Step-Up/Step-Down k (=2,3, ...)-Fibonacci DC-DC Converter Designed by Switched-Capacitor Techniques

A step-up/step-down k(=2, 3, ...)-Fibonacci switched-capacitor (SC) DC-DC converter is proposed in this paper. Unlike conventional Fibonacci step-up converter, the proposed converter can provide not only stepped-up voltages but also stepped-down voltages, where the k-Fibonacci ratios such as Tribonacci numbers, Tetranacci numbers, etc. are demonstrated by using the minimum number of capacitors. Concerning conversion ratios, output voltages and power efficiency, the properties of the proposed converter are investigated by theoretical analysis and simulations. Through simulation program with integrated circuit emphasis (SPICE) simulations and theoretical analysis, the following results are shown: 1. The simulation results show that the proposed converter can achieve not only higher step-up/step-down conversion ratios but also more various kinds of output voltages than conventional converters. 2. The theoretical formula obtained from the theoretical analysis is proved as an effective method for estimating the characteristic of the proposed converter, because the theoretical results corresponded well with the SPICE simulated results.