Reconfigurable switched-capacitor DC-DC converter with adaptive switch modulation and frequency scaling techniques
Journal
Proceedings - IEEE International Symposium on Circuits and Systems
Journal Volume
2021-May
Date Issued
2021
Author(s)
Abstract
A switched-capacitor (SC) step-down DC-DC converter reconfiguring its open-loop topology based on the input voltage to resolve the efficiency issue of single topology is presented in this paper. An adaptive switch modulation (ASM) technique, modulating switch width of the power stage, and a frequency scaling (FS) technique, scaling the sampling rate of the PFM controller, are also proposed to reduce the quiescent current of the converter for light-load efficiency. The prototype converter in 0.25-μm CMOS process with integrated flying capacitors generates a fixed regulated output voltage of 1.8V from an input voltage ranging from 3V to 4.2V. Experimental results show that the gate driving loss and the PFM controller power are decreased by more than 70% with the ASM and FS techniques. The light-load efficiencies are enhanced by 7% and 10% when the input voltage is 3V and 4V, respectively. The transient response time is about 500ns after a step current from 50μA to 10mA. Its power efficiency is high than 70% over a wide load current range with a peak value of 83%. ? 2021 IEEE
Subjects
Light-load efficiency
Low quiescent current
Reconfigurable switched-capacitor DC-DC converter
Dynamic frequency scaling
Efficiency
Frequency modulation
Pulse time modulation
Switching frequency
Topology
Transient analysis
Flying capacitor
Frequency-scaling
Prototype converter
Quiescent currents
Reconfigurable switched capacitors
Step-down dc-dc converters
Switched capacitor
DC-DC converters
SDGs
Type
conference paper