A low-ripple switched-capacitor voltage regulator with decoupling capabilities

In this paper, a switched-capacitor voltage regulator with a very low output ripple and decoupling capability is presented. To implement this regulator, a dual-phase, double fly capacitors configuration is proposed. Besides having a very low output ripple, it is demonstrated how it is very effective in suppressing power input noise as well, for example EMI interferences propagating across the power lines, thus introducing a new concept of active filtering. Being based on switched capacitors, filters based on this concept can be easily placed in an integrated circuit; in addition, unlike traditional analog filters, resonance phenomena are not possible. Because of these characteristics, the proposed converter has been intended for those circuits where it is required to have very clean power sources even in the presence of disturbing magnetic fields, like measurement instruments operating in hard environmental conditions.