A simple approach to a linear control of switched capacitor DC-DC converters in system-on-chip

Switched-capacitor DC-DC converters are easily integrated in CMOS technologies on the contrary to inductive DC-DC converter. They appear as an interesting solution to provide fine grain power management in system-on-chip. Previous works have demonstrated both high efficiency and high power density for several power stage topologies. Many types of controller have been analyzed as those using frequency modulation. This paper proposes a simple method to implement a linear frequency modulation based controller. The power stage is modeled using sampled-data modeling which is an uniform approach. Then the frequency response is used to size a compensation network according to stability and transient requirements. Theoretical results are supported by simulation.