A high-speed converter with light-load improvement circuit and transient detector

This paper presents a high-speed DC-DC converter with light-load improvement circuit using TSMC 0.18μm CMOS process. The proposed DC-DC converter has over 80% efficiency and very fast transient response about 280ns. The maximum loading is 300mA and the required passive components are all at nano-meter level. The high-efficiency DC-DC converter not only can be used in portable electronic devices, but also in tiny wireless sensor nodes because it only needs nano-level passives. To achieve using these small components, the switching frequency must be high enough to reduce the output ripple, but the efficiency will decrease seriously. The light-load improvement circuit effectively improve the efficiency under 40MHz switching frequency and makes this converter have 15% greater efficiency than an ideal linear low-dropout regulator (LDO). This paper also uses a high-bandwidth current sensor to monitor the current through inductor so that the light-load improvement circuit can change the switching frequency by receiving the signal from the current sensor.