DC tolerance analysis of electronic circuits by polyhedral circuits

1noReal equilibrium solutions of electronic circuits are affected by deviation of real characteristics of devices from their nominal values, producing the displacement of solution points from their nominal position. In this paper, a method to determine all the equilibrium regions in which real equilibrium points may fall is presented. The analysis is based on the introduction of the so-called strip characteristics that represent the characteristics of devices affected by tolerances. They are modeled by polyhedral characteristics. Different situations may occur as tolerances grow. A nominal solution point may disappear, or on the other end, some solution point not present with nominal characteristics may appear. These possible events call for a classification of the equilibrium regions in either certain or uncertain, depending on the existence or not of an equilibrium point for any choice of real characteristics. The algorithm adopts linear programming techniques and a clustering algorithm.partially_openopenPastore, StefanoPastore, Stefan

Estimation and control of non-linear and hybrid systems with applications to air-to-air guidance

Issued as Progress report, and Final report, Project no. E-21-67

Global optimization with piecewise linear approximation

textGlobal optimization deals with the development of solution methodologies for nonlinear nonconvex optimization problems. These problems, which could arise in diverse situations ranging from optimizing hydro-power generation schedules to estimating coefficients of non-linear regression models, are difficult for traditional nonlinear solvers that iteratively search the neighborhood around a starting point. The Piecewise Linear Approximation (PLA) method that we study in this dissertation seeks to generate ‘good’ starting points, hopefully ones that lie in the basin of attraction of the globally optimal solution. In this approach, we approximate the non-linear functions in the optimization problem by piecewise linear functions defined over the vertices of a grid that partitions the domain of each nonlinear function into cells. Based on this approximation, we convert the original nonlinear program into a mixed integer program (MIP) and use the solution to this MIP as a starting point for a local nonlinear solver. In this dissertation, we validate the effectiveness of the PLA approach as a global optimization approach by applying it to a diverse set of continuous and discrete nonlinear optimization problems. Further, we develop various modeling and algorithmic strategies for enhancing the basic approach. Our computational results demonstrate that the PLA approach works well on non-convex problems and can, in some cases, provide better solutions than those provided by existing nonlinear solvers.Information, Risk, and Operations Management (IROM

Effect of Clock and Power Gating on Power Distribution Network Noise in 2D and 3D Integrated Circuits

In this work, power supply noise contribution, at a particular node on the power grid, from clock/power gated blocks is maximized at particular time and the synthetic gating patterns of the blocks that result in the maximum noise is obtained for the interval 0 to target time. We utilize wavelet based analysis as wavelets are a natural way of characterizing the time-frequency behavior of the power grid. The gating patterns for the blocks and the maximum supply noise at the Point of Interest at the specified target time obtained via a Linear Programming (LP) formulation (clock gating) and Genetic Algorithm based problem formulation (Power Gating)

A test method for analog circuits : using sensitivity analysis and the singular value decomposition

XVII+C.3hlm.;24c

Bluetooth/WLAN receiver design methodology and IC implementations

Emerging technologies such as Bluetooth and 802.11b (Wi-Fi) have fuelled the growth of the short-range communication industry. Bluetooth, the leading WPAN (wireless personal area network) technology, was designed primarily for cable replacement applications. The first generation Bluetooth products are focused on providing low-cost radio connections among personal electronic devices. In the WLAN (wireless local area network) arena, Wi-Fi appears to be the superior product. Wi-Fi is designed for high speed internet access, with higher radio power and longer distances. Both technologies use the same 2.4GHz ISM band. The differences between Bluetooth and Wi-Fi standard features lead to a natural partitioning of applications. Nowadays, many electronics devices such as laptops and PDAs, support both Bluetooth and Wi-Fi standards to cover a wider range of applications. The cost of supporting both standards, however, is a major concern. Therefore, a dual-mode transceiver is essential to keep the size and cost of such system transceivers at a minimum. A fully integrated low-IF Bluetooth receiver is designed and implemented in a low cost, main stream 0.35um CMOS technology. The system includes the RF front end, frequency synthesizer and baseband blocks. It has -82dBm sensitivity and draws 65mA current. This project involved 6 Ph.D. students and I was in charge of the design of the channel selection complex filter is designed. In the Bluetooth transmitter, a frequency modulator with fine frequency steps is needed to generate the GFSK signal that has +/-160kHz frequency deviation. A low power ROM-less direct digital frequency synthesizer (DDFS) is designed to implement the frequency modulation. The DDFS can be used for any frequency or phase modulation communication systems that require fast frequency switching with fine frequency steps. Another contribution is the implementation of a dual-mode 802.11b/Bluetooth receiver in IBM 0.25um BiCMOS process. Direct-conversion architecture was used for both standards to achieve maximum level of integration and block sharing. I was honored to lead the efforts of 7 Ph.D. students in this project. I was responsible for system level design as well as the design of the variable gain amplifier. The receiver chip consumes 45.6/41.3mA and the sensitivity is -86/-91dBm

Implementation of a Digital Signal Processor (DSP) Based Space Vector Control of AC Induction Motor Drives

The inverters transfer energy from a DC source to a controlled process in the form of pulse trains, using semiconductor switches which are turned on and off at fast repetition rates. This thesis explains in depth how these pulse trains synthesize sine waves. AC waveform generation techniques such as the square wave and Pulse Width Modulation (PWM) are compared in terms of their harmonic elimination capability and fundamental gain control. Various PWM techniques such as bipolar switching, unipolar switching, selective harmonic elimination switching and Space Vector PWM (SVPWM) switching are analyzed and compared in terms of their ability to control harmonic distortion (THD), minimize switching losses, control fundamental gain and maximize DC bus utilization capacity. The selective harmonic elimination technique is covered in depth including a technique that utilizes a neural network controller to remove a selected set of harmonics. This thesis focuses on Space Vector PWM (SVPWM) technique since it has many advantages over other conventional methods such as sine wave PWM. Thus, the SVPWM theory and experimental analysis is presented in depth. The SVPWM technique was realized using the state-of-the- art power electronics hardware and Digital Signal Processing (DSP) software. The experimental procedure and harmonics analysis of the DSP based SVPWM output waveforms and inverter output voltages and currents are presented. The experiments were carried out using power electronics development modules such as the Texas Instrument’s TMS320LF2407 DSK (eZdsp), Digital Motor Controller (DMC1500), and the VisSim™/TI C2000 Rapid Prototyper software package and a three-phase AC induction motor. The VisSim™/TI C2000 Rapid Prototyper was extensively used to model an AC induction motor control sub system that generates real time SVPWM waveforms to control a three-phase induction motor. The AC induction motor control sub-system was implemented using the principle of constant Volts/Hertz (V/Hz) profile. S\u27 averal measurements and observations of the phase-voltages, line-voltages and phase currents were made to observe the quality of the power produced using the SVPWM technique. The SVPWM waveforms were simulated using MATi_AB™ software and the VisSim™/TI C2000 Rapid Protctyper software. These simulated SVPWM waveforms were compared with the DSP generated SVPWM waveforms and the inverter output. The completed project will give the user the ability to use the VisSim™/TI C2000 Rapid Prototyper software to generate SVPWM waveform and power the DSP controller (eZdsp), interface the DMC1500 (inverter) with the eZdsp and control a three-phase induction motor. An extension of the conventional three-phase SVPWM to higher order phase systems is reviewed. An overview of the principle of sensorless variable speed three-phase AC motor drives with closed-loop speed control is included