Algebraic synthesis of Fibonacci Switched Capacitor Converters

Abstract

-A simple algebraic approach to synthesis Fibonacci Switched Capacitor Converters (SCC) was developed. The proposed approach reduces the power losses by increasing the number of target voltages. The synthesized Fibonacci SCC is compatible with the binary SCC and uses the same switch network. This feature is unique, since it provides the option to switch between the binary and Fibonacci target voltages, increasing thereby the resolution of attainable conversion ratios. The theoretical results were verified by experiments.

Unified algebraic synthesis of generalized Fibonacci Switched Capacitor Converters

“…Applying the relationship η=Vo/VTRG, the minimum efficiency (just before reaching the 1/7 gain) is 71.4%. For the same gain range, the minimum efficiency of the Fibonacci SCC [6], [7] would be 62.5%. Hence, considerable improvement is obtained even at the very low conversion ratios.…”

“…Note that for n flying capacitors and h = k = 2, the highest conversion ratio is equal to the regular Fibonacci number Fn+2. This case is of practical importance if there is a need to build a specific charge pump and was reported in [6], [7]. 1 0 1 -1 0 0 1 -1 1 1 -1 0 1 1 -1 1 0 1 -1 1 1 0 1 -1 -1 1 -1 -1 1 1 -1 0 0 1 -1 1 -1 1 0 -1 0 1 0 -1 1 1 -1 -1 0 1 -1 0 -1 0 1 0 -1 1 0 -1 -1 0 1 1 -1 1 0 0 -1 Fig.…”

“…Attempts to introduce multiple values of M have resulted hitherto in circuits with a large number of capacitors and switches that increase the power losses. An effective way to realize many target voltages is the combination of the binary [4], [5] and Fibonacci SCC [6], [7]. The behavior of this combination is depicted by the solid line in Fig.…”

The best of both worlds: Fibonacci and binary switched capacitor converters combined

“…The objective of this study was to introduce additional target voltages to the binary SCC without adding capacitors or switches. This paper covers in detail all the steps involved in the synthesis of a Fibonacci SCC proposed in [6], including the derivation of the analytical expressions of the losses that are Req. The dashed line in Fig.…”

A New Control Method to Reduce Parasitic Losses in a Ring-Type DC-DC Converter

“…Furthermore, SC power converters came to be used for a building block of energy harvesting applications in recent years [4], [5]. For these application systems, several kinds of SC circuit topologies have been proposed in past studies: charge-pump circuits [1]- [6], series-parallel type converters [7], Fibonacci-type converter [8], and so on. Among others, the ring-type converter [9]- [13] is the unique converter which can achieve step-up/step-down conversion.…”