Lossless voltage regulation and control of the resonant switched-capacitor DC-DC converter

Abstract

Abstract-This paper presents an approach for nominally lossless regulation of the output voltage, and for design of tight closed-loop voltage control of a resonant switched-capacitor (ResSC) dc-dc converter. A switching pattern for the ResSC dc-dc converter that enables wide range lossless voltage regulation and zero voltage switching (ZVS) is developed. An appropriate small signal model is derived based on the generalized averaging method. In view of the dynamics of the developed small signal transfer functions, a compensation method based on a minor phase loop is introduced to stabilize the system. The steady state and transient responses of the system are evaluated based on the developed model. The performance of the proposed controller is verified by a switch-based simulation in a design example for on-chip power delivery application.

Optimized Resonators for Piezoelectric Power Conversion

“…Although our optimizations do not take into account the dielectric loss due to the complexity it adds to the analytical solutions, we can look at the impact of dielectric loss. From (7) and (8) a ratio of the power lost in the resonator dielectric to the power lost in the motional branch can be calculated for operation with an optimally sized resonator and a 1:1 conversion ratio:…”

“…Due to the dc block characteristics of the piezoelectric resonator, standard topologies such as the buck or boost converter are not applicable. Instead, suitable circuit topologies are similar to those of resonant switched capacitor converters, which can achieve zero voltage switching (ZVS) and a variable conversion ratio using piezoelectric resonators in place of the conventional LC resonant circuit [7], [8], [9], [10]. Previous researchers have demonstrated piezoelectric resonator based dc-dc converters operating at high efficiency [10], [11], [12] and the optimal switching patterns have been enumerated by [10].…”

A Stacked Piezoelectric Converter Using a Segmented IDT Lithium Niobate Resonator

“…However, due to the charge balance requirements in the piezoelectric resonator, operation under large conversion ratios leads to excessive circulating power and comparatively low efficiency. To increase efficiency at larger conversion ratios, other works have investigated combining piezoelectric topologies with switched capacitor topologies [12], [13], [14]. This paper presents a converter topology that reduces voltage stress and achieves high efficiency over a wider conversion ratio by using two stacked switching cells that each drive a piezoelectric resonator.…”