Engineering Commons^™

A Charge-Recycling Scheme And Ultra Low Voltage Self-Startup Charge Pump For Highly Energy Efficient Mixed Signal Systems-On-A-Chip, Chandradevi Ulaganathan

Doctoral Dissertations

The advent of battery operated sensor-based electronic systems has provided a pressing need to design energy-efficient, ultra-low power integrated circuits as a means to improve the battery lifetime. This dissertation describes a scheme to lower the power requirement of a digital circuit through the use of charge-recycling and dynamic supply-voltage scaling techniques. The novel charge-recycling scheme proposed in this research demonstrates the feasibility of operating digital circuits using the charge scavenged from the leakage and dynamic load currents inherent to digital design. The proposed scheme efficiently gathers the “ground-bound” charge into storage capacitor banks. This reclaimed charge is then subsequently …

Characterization And Implementation Of An Injection Locked Frequency Divider Based On Relaxation Oscillator, Kai Zhu

Doctoral Dissertations

There has been a dramatic increase in wireless awareness among the user community in the past few years. As the wireless communication devices require more integration in terms of both hardware and software, the low-power integrated circuit (IC) solution has gained higher dedication and will dominate in the future radio-frequency IC (RFIC) design. Complementary Metal-Oxide Semiconductor (CMOS) process is extremely attractive for such applications because of its low cost and the possibility to integrate baseband and high frequency circuits on the same chip. The transceiver is often the most power-hungry block in a wireless communication system. The frequency divider (prescaler) …

Real-Time Selective Harmonic Minimization For Multilevel Inverters Using Genetic Algorithm And Artificial Neural Network Angle Generation, Faete Jacques Teixeira Filho

Doctoral Dissertations

This work approximates the selective harmonic elimination problem using Artificial Neural Networks (ANN) to generate the switching angles in an 11-level full bridge cascade inverter powered by five varying DC input sources. Each of the five full bridges of the cascade inverter was connected to a separate 195W solar panel. The angles were chosen such that the fundamental was kept constant and the low order harmonics were minimized or eliminated. A non-deterministic method is used to solve the system for the angles and to obtain the data set for the ANN training. The method also provides a set of acceptable …

Design And Control Of High Power Density Motor Drive, Dong Jiang

Doctoral Dissertations

This dissertation aims at developing techniques to achieve high power density in motor drives under the performance requirements for transportation system. Four main factors influencing the power density are the main objects of the dissertation: devices, passive components, pulse width modulation (PWM) methods and motor control methods.

Firstly, the application of SiC devices could improve the power density of the motor drive. This dissertation developed a method of characterizing the SiC device performance in phase-leg with loss estimation, and claimed that with SiC Schottky Barrier Diode the advantage of SiC JFET could benefit the motor drive especially at high temperature. …

Wide-Area Measurement Application And Power System Dynamics, Lang Chen

Doctoral Dissertations

Frequency monitoring network (FNET) is a GPS-synchronized distribution-level phasor measurement system. It is a powerful synchronized monitoring network for large-area power systems that provides significant information and data for power system situational awareness, real time and post-event analysis, and other important aspects of bulk systems. This work explored FNET measurements and utilized them for different applications and power system analysis.

An island system was built and validated with FNET measurements to study the stability of the OTEC integration. FNET measurements were also used to validate a large system model like the U.S. Eastern Interconnection. It tries to match the simulation …

Design Of Wireless Power Transfer And Data Telemetry System For Biomedical Applications, Ashraf Bin Islam

Doctoral Dissertations

With the advancement of biomedical instrumentation technologies sensor based remote healthcare monitoring system is gaining more attention day by day. In this system wearable and implantable sensors are placed outside or inside of the human body. Certain sensors are needed to be placed inside the human body to acquire the information on the vital physiological phenomena such as glucose, lactate, pH, oxygen, etc. These implantable sensors have associated circuits for sensor signal processing and data transmission. Powering the circuit is always a crucial design issue. Batteries cannot be used in implantable sensors which can come in contact with the blood …

In Situ Preconcentration By Ac Electrokinetics For Rapid And Sensitive Nanoparticle Detection, Kai Yang

Doctoral Dissertations

Reducing cost and time is a major concern in clinical diagnostics. Current molecular diagnostics are multi-step processes that usually take at least several hours or even days to complete multiple reagents delivery, incubations and several washing processes. This highly labor-intensive work and lack of automation could result in reduced reliability and low efficiency. The Laboratory-on-a-chip (LOC), taking advantage of the merger and development of microfluidics and biosensor technology, has shown promise towards a solution for performing analytical tests in a self-contained and compact unit, enabling earlier and decentralized testing. However, challenges are to integrate the fluid regulatory elements on a …

A High -Temperature, High-Voltage, Fast Response Time Linear Regulator In 0.8um Bcd-On-Soi, Chia Hung Su

Doctoral Dissertations

The sale of hybrid electric vehicles (HEVs) has increased tenfold from the year 2001 to 2009 [1]. With this the demand for high temperature electronics has also increased dramatically making, high temperature electronics for HEV applications desirable in the engine compartment, power train, and brakes where the ambient temperature normally exceeds 150°C. Power converters (i.e. DC-DC converter, DC-AC inverter) inside the HEVs require gate drivers to control the power switches. An integrated gate driver circuit has been realized in 0.8-um BCD-on-SOI process. This gate driver IC needs a step-down voltage regulator to convert the unregulated high input DC voltage (VDDH) …

A Novel Frequency Based Current-To-Digital Converter With Programmable Dynamic Range, Xiaoyan Yu

Doctoral Dissertations

This work describes a novel frequency based Current to Digital converter, which would be fully realizable on a single chip.

Biological systems make use of delay line techniques to compute many things critical to the life of an animal. Seeking to build up such a system, we are adapting the auditory localization circuit found in barn owls to detect and compute the magnitude of an input current.

The increasing drive to produce ultra low-power circuits necessitates the use of very small currents. Frequently these currents need to accurately measured, but current solutions typically involve off-chip measurements. These are usually slow, …

Reconfigurable Rf Front End Components For Multi-Radio Platform Applications, Chunna Zhang

Doctoral Dissertations

The multi-service requirements of the 3G and 4G communication systems, and their backward compatibility requirements, create challenges for the antenna and RF front-end designs with multi-band and wide-band techniques. These challenges include: multiple filters, which are lossy, bulky, and expensive, are needed in the system; device board size limitation and the associated isolation problems caused by the limited space and crowd circuits; and the insertion loss issues created by the single-pole-multi-through antenna switch.

As will be shown, reconfigurable antennas can perform portions of the filter functions, which can help solve the multiple filters problem. Additionally, reconfigurable RF circuits can decrease …

Low-Voltage Analog Circuit Design Using The Adaptively Biased Body-Driven Circuit Technique, Stephen Christopher Terry

Doctoral Dissertations

The scaling of MOSFET dimensions and power supply voltage, in conjunction with an increase in system- and circuit-level performance requirements, are the most important factors driving the development of new technologies and design techniques for analog and mixed-signal integrated circuits. Though scaling has been a fact of life for analog circuit designers for many years, the approaching 1-V and sub-1-V power supplies, combined with applications that have increasingly divergent technology requirements, means that the analog and mixed-signal IC designs of the future will probably look quite different from those of the past. Foremost among the challenges that analog designers will …