A Fast-Transient Switched-Capacitor DC-DC Converter with a Current Sensing Control Technique.
Journal
62nd IEEE International Midwest Symposium on Circuits and Systems, MWSCAS 2019, Dallas, TX, USA, August 4-7, 2019
Pages
806-809
Date Issued
2019
Author(s)
Abstract
A low-power switched-capacitor step-down DC-DC converter using the proposed current sensing control technique to enhance the transient response is presented in this paper. By sensing the current outflow from the DC-DC converter and the load current simultaneously, the proposed technique scales the switching frequency (Fsw) accordingly from the very beginning of the load or the line transient. It leads to better transient response without depending on the output capacitance. It is suitable for sensor applications which usually use an LDO with a large output capacitor, resulting in lower efficiency. The converter is implemented in a 0.25-μm CMOS process with integrated flying capacitors and generates a fixed regulated output voltage of 1.8V from an input voltage ranging from 3.8V to 5.4V. From the measurement results, the transient response time is about 0.3μs after a step load current from 20μA to 2.5mA which is sufficient for low-power sensor applications. Its power efficiency (η) is higher than 70% over a wide range of the load current with a peak value of 72.8%.
SDGs
Type
conference paper