Zheng Li

Graduation Semester and Year

2005

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Electrical Engineering

Department

Electrical Engineering

First Advisor

Ronald L Carter

Abstract

Power management is playing a significant role in modern electronics. Good power management is especially important for portable devices that rely on batteries. By smartly managing how the power is directed to different components of a system, e.g., reducing power to components that are not being used, the efficiency as well as the battery lifetime can be doubled or tripled. There exists a large family of integrated circuits (IC) that are used for power management, e.g., linear regulators, switching regulators, power controllers, hot swap controllers, etc. The voltage reference is one of the key components in this family. For high precision, the drift of a reference voltage needs to be minimized. This is especially true for the drift caused by temperature variation. This drift can be reduced by means of compensation. High performance of compensation is achieved through curvature correction. A novel approach for curvature compensation is proposed in this work. It is suitable for extra-low-voltage operation with micro power dissipation. The overall performance of reference circuits are characterized by current efficiency, line regulation, load regulation, power supply rejection ratio, and noise in addition to temperature drift. To take into consideration all of these in a functionality analysis, a strategy is developed based on the General Systems Performance Theory. In this strategy, each aspect of performance is evaluated based on the fact how well this aspect of performance satisfies the predetermined task demands. Then all these individual evaluation results are combined to represent the overall performance. The line regulations performance in the designed reference circuits are improved by introducing a linear voltage regulator. The error amplifier is one of the critical elements in the linear regulator. It needs to have high current driving capability as well as high efficiency. Thus error amplifiers are designed with class AB output stages. Finally the noisy raw supply voltages go through the designed linear regulator before being fed to the reference circuits, and the line regulation performance is enhanced dramatically. Also the linear regulator is applied to a variable gain amplifier to reduce the dependence of gain on power supply voltage.

Disciplines

Electrical and Computer Engineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

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