An Ultra Low Power Digital to Analog Converter Optimized for Small Format LCD Applications

Liquid crystal displays (LCDs) for mobile applications present a unique design challenge. These small format displays can be found primarily in cell phones and PDAs which are devices that have particularly stringent power requirements. At the same time, the displays are increasing in resolution with every generation. This is creating demand for new LCD display technologies. The predominant amorphous thin film transistor technology is no longer feasible in the new high resolution small format screens due to the fact that the displays require too many connections to the driver and the aperture ratios do not allow high density displays. New technologies such as low temperature polysilicon (LTPS) displays continue to shrink in size and increase in resolution. LTPS technology enables the display manufacturer to create relatively high quality transistors on the glass. This allows for a display architecture which integrates the gate driver on the glass. Newer LTPS LCDs also enable a high level of multiplexing the sources lines on the glass which allows for a much simpler connection to the display driver chip. The electronic drivers for these display applications must adhere to strict power and area budgets. This work describes a low-power, area efficient, scalable, digital-to-analog conversion (DAC) integrated circuit architecture optimized for driving small format LCDs. The display driver is based on a twelve channel, 9-bit DAC driver. This architecture, suitable for % VGA resolution displays, exhibited a 2 MSPS conversion rate, less than 300 pW power dissipation per channel using a 5 V supply, and a die area of 0.042 mm per DAC. A new performance standard is set for DAC display drivers in joules per bit areal density

A Piecewise Linear Approximation D/A Converter for Small Format LCD Applications

Low power operation is a driving requirement for the advancement of portable consumer electronics. As products get smaller and have more functionality the device integration requirements get tighter. This is certainly true of small format LCD applications like PDAs and cell phones. Recent advances in LCD technology have allowed for advanced circuitry to be built on the glass. This allows for the unique opportunity to integrate the LCD column driver with other circuitry rather than the traditional flip chip mounting on the glass. The integration of these D/A converters with digital circuitry presents a new set of design considerations. These considerations allow for the exploration of non-traditional architectures and algorithms. This work will explore these design considerations in detail and present a novel algorithm for conversion as well as a system implementation of this algorithm. The system implementation is compared to a standard linear converter to weigh the relative advantages of each. A high performance dynamically biased amplifier is developed for use in the D/A converter. This amplifier has a high slew rate while consuming a small amount of quiescent power

Implementation of a MSP430-based ultrasonic distance measurement module

This application report describes a distance-measuring system based on ultrasonic sound utilizing the MSP430F413 ultralow-power microcontroller. The system transmits a burst of ultrasonic sound waves towards the subject and then receives the corresponding echo. The MSP430 integrated analog comparator Comparator_A is used to detect the arrival of the echo to the system. The time taken for the ultrasonic burst to travel the distance from the system to the subject and back to the system is accurately measured by the MSP430. Assuming the speed of sound in air at room temperature to be 1100 ft/s, the MSP430 computes the distance between the system and the subject and displays it using a two-digit static LCD driven by its integrated LCD driver. The distance is displayed in inches with an accuracy of ±1 inch. The minimum distance that this system can measure is eight inches and is limited by the transmitter’s transducer settling-time. The maximum distance that can be measured is ninetynine inches. The amplitude of the echo depends on the reflecting material, shape, and size. Sound-absorbing targets such as carpets and reflecting surfaces less than two square feet in area reflect poorly. The maximum measurable range is lower for such subjects. If the amplitude of the echo received by the system is so low that it is not detectable by the Comparator_A, the system goes out of range. This is indicated by displaying the error message E

Smart Recloser

The goal of this project was to develop an intelligent recloser system that is able to differentiate between a temporary and a persistent fault, and then take proper action. The intended use of this system is to increase reliability and energy quality. The system was realized by using a non-invasive method to monitor the soundness of the line. Through signal processing, this information is converted into logic that a microprocessor can use to control the recloser

Modular Environmental Controller for Sustainable Agriculture

The objective of this project was to design and implement a modular control system for use in controlled environment agriculture. The system is comprised of a TI Cortex A-8 based master node which communicates with PIC18 based sensor and control nodes using the CAN bus standard over standard Ethernet cable. The network cable carries both serial communications and 24V power for nodes on the network for ease of installation and expandability. The system can be monitored and controlled via a dynamic web page. A proof of concept was built which accurately monitors CO2 concentration, relative humidity, and temperature and controls standard outlets

Design, implementation, and verification of an FPGA-based control system for a permanent-magnet motor drive built upon a three-phase four-level active-clamped inverter

At the present time, a DE0 board from Terasic/Altera, which includes a Field Programmable Gate Array (FPGA) Cyclone III, is used to control a three-phase four-level active-clamped inverter which drives a permanent-magnet motor. The project consists in designing a new FPGA-based control system that substitutes the current control system based on the DE0 board. The novel control system will consist of a single board containing a new FPGA more suitable for the specific application, the analog-to-digital converters, and all the necessary auxiliary circuitry. The FPGA content wi[ANGLÈS] The present work summarizes the work and knowledge acquired by the author during its Master’s Thesis in the Research Group in Power Electronics, GREP. The development is based on the Multilevel Active-Clamped (MAC) power converter prototype, which was initially developed by GREP. Serving as a great introduction to the multilevel converter state-of-the-art, the prototype was tested and it was proved the need for a custom FPGA-based control platform board to drive a PMSM. The design of the board is then performed following the requirements established by the research group and the results obtained from the initial tests. Issues as power decoupling, signal conditioning and grounding strategies are discussed in the following chapters.[CASTELLÀ] La memoria aquí presentada recoge el trabajo y el conocimiento adquirido por el autor durante la elaboración de su tesis de Máster dentro del Grupo de Investigación en Electrónica de Potencia de la Universidad Politécnica de Cataluña, GREP. El trabajo elaborado se desarrolla en torno al prototipo, previamente desarrollado por los miembros del GREP, de un convertidor de potencia multinivel de tipo MAC (Multilevel Active-Clamped). La familiarización con los últimos avances en conversores multinivel se lleva a cabo mediante la fase de pruebas experimentales con este dispositivo, que a su vez demuestran la necesidad de diseñar una placa controladora específica basada en FPGA para mover un motor de imanes permanentes. Esta placa de control se diseña siguiendo los requisitos establecidos por el GREP y las necesidades surgidas en la fase de experimentación. En los capítulos del trabajo se tratan temas como el desacoplo de la alimentación, acondicionamiento de señales o metodologías de diseño de planos de masa.[CATALÀ] La memòria aquí presentada recull el treball i el coneixement adquirit per l'autor durant l'elaboració de la seva tesi de Màster dins del Grup de Recerca en Electrònica de Potència de la Universitat Politècnica de Catalunya, GREP. El treball es desenvolupa en torn al prototipus, prèviament desenvolupat pels membres del GREP, d'un convertidor de potència multinivell de tipus MAC (Multilevel Active-Clamped). La familiarització amb els darrers avanços en convertidors multinivell s'ha dut a terme mitjançant la fase de proves experimentals amb aquest prototipus, les quals han demostrat la necessitat de dissenyar una placa controladora específica basada en FPGA per controlar un motor d'imants permanents. Aquesta placa de control s'ha dissenyat seguint els requisits establerts pel GREP i les necessitats aparegudes en la fase d'experimentació. En els capítols del treball es tracten temes com el desacoblament de l'alimentació, condicionament de senyals o metodologies de disseny de plans de massa

Digital Guitar Effects Pedal

The Digital Guitar Effects Pedal assists guitarists in creating music by implementing several useful functions. The pedal takes an analog input signal from an electric guitar, performs digital operations on it, and outputs a modified analog signal to an external guitar amplifier. Pedal functions include: an easy-to-use instrument tuner, a looper which records and plays back music segments, a tap tempo mode allowing easy synchronization with other instruments, and various guitar effects (distortion, echo, and vibrato, among other examples). The pedal user interface displays the current selected function, and allows easy switching between effects

An Activity Monitor for Diabetic Individuals

An activity monitor that diabetic individuals can wear continuously will provide important information on how these individuals should make adjustments to their exercise, diet, and insulin dosage in order to maintain a healthy lifestyle. The device is composed of both heart rate sensing components and components to measure the magnitude of physical movement. The energy expenditure is calculated using an algorithm that continuously adjusts depending on the type of activity. The system display provides the carbohydrates burned in order to be adjunctive to carbohydrate counting, a common technique used for glucose management