Reconfigurable Switched Capacitor DC-DC Converter Using On-Chip Ferroelectric Capacitors

A reconfigurable switched capacitor DC-DC converter featuring high density ferroelectric capacitors (Fe-Caps) for charge transfer is designed in this work. The converter supports four gain settings (1-2/3-1/2-1/3) to supply wide output voltage range and is split in four modules for output voltage ripple reduction. The control circuit exploits dynamic gain selection and Pulse Frequency Modulation (PFM) for efficient output voltage regulation of the multi-phased converter. The chip is fabricated in 130 nm CMOS process and the system occupies an area of 0.366 sq.mm. It supports output voltage of 0.4V to 1.1V from 1.5V input while delivering load current of 20µA to 1mA and achieves a peak efficiency of 93% including the control circuit overhead.