Research On Integrated Power Management Technology For Modern Portable Devices

As the rapid development of electronics and integrated circuit technology, modern portable devices have developed to highly complex systems. Correspondingly, the power management of the system has become an inevitable challenge in design. Tightening power budget, limiting power and heat loss requirement have posed great challenge to the designing of a portable system, which require better overall performance level, higher conversion efficiency, and stronger voltage and energy scheduling abilities including higher efficiency, smaller volume as well as more advanced adaptability to increasing system complexity and shorter time-to-market.In view of this, this dissertation focuses on research of high-performance integrated power management system suitable for modern portable system as well as the related key technical problems to find out the corresponding solutions.In order to sense battery characteristics and optimize its charging/discharging so as to maximize its working time, the energy consumption perception technology is developed, which results in the optimal balance among battery run time, compatibility, volume and effective heat management of a power system and the realization of comprehensive energy control and management including highly efficient and intelligent charging control in switch mode, programmable input current limiting strategy and the input current limit loop for adapting to different types of power supplies varying from USB port to wall adaptor power supply. In addition, a unique load distribution function based on load priority principle is introduced to guarantee that the device supplies its surplus energy to battery charging while working normally so as to reduce the charge/discharge frequencies of battery and extend its lifetime.To meet the requirements of low power consumption, high processor performance and devices demands, a multi-output high efficiency DC-DC switch convert technique is developed, which uses a seamless transition step down/step up switch converter for nominal output channel to extend battery work time and the modular emulated current mode switch converter for lower voltage output channel to improve the design compatibility. Dynamic voltage regulating and energy distribution technologies are developed, which introduce the continuous, discontinuous and open-loop controlled multi-mode control method respectively in different load conditions to realize high efficiency regulating during the entire load range. In order to improve the load step transient response, a special linear-nonlinear mixed control is proposed.Considering the problem of current sensing loss in current mode control, a Gm-C filter based auto-calibration lossless inductor current sensing technique is proposed. The research is mainly focused on low offset, wide input common mode range, high output impedance and programmable trans-conductance of Gm-C circuit design. This technique is successfully applied to peak current mode and average current mode control.All the above power management technologies are realized in integrated circuit, and verified by simulation, tape-out and test.