Switched - Capacitor Filter Based Type - III Compensation for Voltage - Mode Control of Switched - Mode Buck

BAWA, GAURAV. Switched-Capacitor Filter Based Type-III Compensation for VoltageMode Control of Switched-Mode Buck Converters. (Under the direction of Dr. Alex Q. Huang). In this dissertation, we propose a novel technique for the voltage-mode control of switchedmode fixed-frequency Buck Converters using Switched-Capacitor Filters (SCF). The salient features of the analog sampled-data Type-III filter embodiment (using SCF) is a monolithic solution, automatic scalability of the filter’s transfer function w.r.t. the Buck Converter’s switching frequency, and moderate on-chip area and power consumption. While the proposed technique is aimed to explore a new design-space, it was observed that it can potentially combine the performance benefits of the conventional all-analog (power efficiency) and alldigital implementations (integration and programmability) of the Type-III compensation. In our prototype, the proposed Type-III SCF-based voltage-mode controller Integrated Circuit (IC) is implemented in Texas Instruments’ 0.36-μm BCD (Bipolar-CMOSDMOS) technology. The IC is configured to control the Buck Converter for two programmable switching frequencies of 500 KHz and 1 MHz. The IC consumes 1.1 mA of static current from a 3.3 V power supply, and has an active-area of ~ 0.65 mm. The theoretical foundations have been validated by performing closed-loop load transient response and open-loop frequency response experiments; while operating the controller IC in closed-loop configuration with a Buck converter power stage. © Copyright 2013 by Gaurav Bawa All Rights Reserved Switched-Capacitor Filter Based Type-III Compensation for Voltage-Mode Control of Switched-Mode Buck Converters