This paper presents a LED driver based on a new Hybrid-Switched Capacitor Converter (H-SCC) operating in the MHz range, which uses the internal pulsed nodes of a Dickson converter and an LC output network to provide output current dimming. The converter is implemented using 5V integrated capacitors and switches in a 0.18μm bulk CMOS technology. The experimental results show that the proposed LED driver has a power density of 122mW/mm2 and an efficiency of 79%, and only needs a small 40nH inductor.

In this paper, a multiple output dc-dc converter is proposed. Pulse frequency modulation (PFM), pulse width modulation (PWM) and phase delay (PD) methods are used to regulate output voltages. Two of the output voltages are regulated by PWM, 2 of them by PFM, and the other one by PD. Five regulated outputs are obtained by using only two active switches. The switches can be operated at different switching frequencies. A hardware prototype was implemented that has 1.5V/0.5A, 3.3V/1A, 12V/0.5A, -12V/0.5A and 5V/1A outputs and the efficiency is 89% at the rated power.

The internal nodes of switched capacitor converters can be used to provide multiple pulsed width modulated voltages that, in combination with filter inductors, can extend the available dc outputs. Such converter architecture requires models that accurately predict the behaviour of switched capacitor converters operated in current output mode. Based on the well-known output impedance model, a new circuit representation is proposed for converters with multiple current-loaded outputs. A characterization methodology is developed to determine the parameters of said model. Predictions of the new model compare favorably to circuit simulations and experimental measurements.

Demand for high power density and miniaturization are pushing the application limits of Switched Capacitor Converters (SCCs) to new areas. Their benefit has up to now been used only in low power application ICs such as memories, or mobile phone backlighting where efficiency is not critical and magnetic components are not available. Recently, research in SCCs is demonstrating that their benefits can be extended to high power density systems, achieving efficiency levels comparable to classical inductive SMPS. These new concepts consider advanced control schemes or hybrid combinations of SCCs and inductive switching, and require better understandings of the SCC and its appropriate models. This work presents a new methodology to model hybrid combinations of SCCs and inductors. The well-known vector charge flow analysis for Switched Capacitor Converters is reviewed and extended in order to accurately model the behavior of a SCC when any of the internal nodes is loaded and controlled by Pulse-Width-Modulation. Results of the analysis compare favorably to behavioral simulations.

This work presents the first design and modelling of bonding-wire-based triangular spiral inductors (Fig. 1), targeting their application to on-chip switching power converters. It is demonstrated that the equilateral triangular shape compared to other polygonal shapes best balances the inductive density as well as the total Equivalent Series Resistance (ESR). Afterwards, a design procedure is presented in order to optimize the inductor design, in terms of ESR and occupied area reduction. Finally, finite-elements simulation results of an optimized design (27 nH, 1 Ω) are presented to validate the proposed expressions.