Personnel

FICs - Prof. Philip K. T. Mok

Description

Using multiple supply voltage for different functional blocks in VLSI design has become a standard and widely adopted technique to reduce power consumption in portable electronics devices such as cellular phones, personal-digital-assistance (PDA) phones and multimedia players. On the other hand, to reduce the size and weight of these portable devices, there is only one rechargeable battery available to supply power to these different functional blocks. Therefore, there are many dc-dc power converters inside these portable devices to generate different supply voltages for different functional blocks. For all dc-dc converters, the inductive-type switched mode power converter (or sometime simply named as switched-mode power converter, SMPC) is the most commonly used dc-dc converter in power management circuit design as it can provide higher power efficiency compared with the switch-capacitor power converter and linear regulator. However, each SMPC requires one inductor for power conversion. This inductor will not be able to be integrated in monolithic integrated circuit (IC) implementation and will increase the physical size and weight of the portable equipment. Current research has been focused on how to use a minimum number of inductors in SMPC design to produce many different output voltages. Recently proposed single-inductor multiple-output (SIMO) switching converters provide a potential solution. However, the current designs of SIMO converters have many limitations and are not optimized in several aspects. As a result, these SIMO converters can only be applied in limited applications for portable electronic devices. One of the main issues of SIMO converters is the cross-regulation. Cross-regulation means that if there is any disturbance due to load transients in one of the output terminals, the disturbance will couple to the other output terminals. With cross-regulation, the SIMO converter will not be able to provide steady voltages to different functional blocks of the portable devices. How to prevent the output voltage of each individual output terminal affecting the output voltage of other terminals becomes very critical for applying SIMO converters to portable devices application. Thus the objective of this proposal is to develop a new control method for SIMO converters. The focus will be on how to minimize the cross-regulation of the SIMO converter such that this converter can be applied in most applications for portable electronics devices. Other issues related to SIMO converter performance such as response time, power efficiency, etc. will also be explored in this project.

Source: RGC | ITF