Personnel

FICs - Prof. Philip K. T. Mok

Description

Dynamic Voltage and Frequency Scaling (DVFS) has been widely used as one of the key techniques in managing the power consumption of microprocessor. The basic idea of DVFS is to lower the supply voltage and clock frequency of the microprocessor when it is idling or having low computing activities in order to save power. During high computing activities, supply voltage and clock frequency of the microprocessor increase to boost up the computing power. DVFS technique needs a switching converter with a fast reference-tracking, which means the converter output voltage needs to change quickly with respect to the sudden change in its reference voltage. In order to further enhance the overall performance of the new generation of microprocessor for handheld portable devices, the increase and decrease of the power supply voltage for the future DVFS technique will be more frequent, more rapid and with a finer voltage steps. This poses a very stringent requirement for reference-tracking in switching converter design. In particular, one of the most important criteria in reference-tracking is not to allow any overshoot or undershoot of the output voltage during the fast reference-tracking operation. The overshoots or undershoots will degrade the reliability and performance of the microprocessor. This project involves the design of on-chip switching DC-DC converter for DFVS applications. Switching converter will be used as the DC-DC converter for the microprocessor as it will provide high efficiency (close to 95%) with various voltage and current ranges compared with other DC-DC converters such as linear regulator and charge pump circuit. Some existing switching converters have fast reference-tracking capability but with large overshoots and undershoots during the reference-tracking. In this project, switching converter with an accurate turn-on and turn-off sequence for DVFS applications will be developed to eliminate the overshoots and undershoots.

Source: RGC | ITF