Understanding the non-ideal characteristics of switched-capacitor DC-DC converters

With the availability of high-quality integrated capacitors, capacitive-type DC-DC converter has become a good candidate for high-efficient on-chip power conversions. Besides for using to generate some high biasing voltages, the converter can also be used for converting the available supply voltage to the continuously down-scaled supply voltage in the advanced CMOS circuits. Unlike the inductive-type converters which have been well-understood, the design and operation of the capacitive-type converters are still required some further investigations because of its new applications and some non-ideal characteristics of CMOS switches and capacitors. This paper aims at giving an overview on these issues.