串行显示驱动器MC14489在紧凑型单片机系统中的应用

本文介绍了ＭＣ１４４８９串行显示驱动器的性能特点、工作原理及其紧凑型单片机系统中物应用。     

机载SAR稳定平台直流力矩电机驱动器

介绍了稳定平台直流力矩电机驱动器的系统组成,包括单片机、R/D变换器、脉冲宽度调制(PWM)功放电路、A/D和D/A电路、通信接口电路。详细阐述了直流力矩电机驱动器需要解决的关键技术问题。最后,给出了稳定精度试验结果。     

在嵌入式系统中用FPGA进行开发的几个发展方向

顾名思义,嵌入式系统指的是嵌入到系统内部的计算机系统,是面向特定应用设计的专用计算机系统.早期的嵌入式系统一般是以通用处理器或单片机为核心,在外围电路中加入存储器、功率驱动器、通信接口、显示接口、人机输入接口等外围接口,再加上应用软件,有些还加上了嵌入式操作系统,从而构成完整的系统.     

串行显示驱动器件MC14499在AT89C2051单片机系统中的应用

文章介绍了串行显示驱动器件ＭＣ１４４９９的性能特点及其在ＡＴ８９Ｃ２０５１单片机系统中的应用。     

基于C8051F020单片机的步进电机驱动器

介绍一种利用C8051F020单片机为控制核心的步进电机驱动器。该驱动器应用斩波恒流细分驱动方式,充分利用C8051F020单片机集成度高、功能多的特点;同时运用驱动集成电路IR2304,大大缩小电路体积并减少电源品种,使驱动器具有驱动平稳、电路简单、可靠性高等优点。     

基于单片机和CPLD的步进电机细分驱动系统

介绍了一种采用单片机和CPLD(Complex Programmable Logic Device)实现步进电机细分驱动的方法。利用单片机来设定电机的转速、转向。由CPLD产生阶梯脉冲经过DAC变换,形成阶梯形电压信号以控制步进电机每相绕组在各时刻的电压,从而实现步进电机的细分驱动。采用CPLD大大简化了系统的外围硬件电路结构,提高了系统的抗干扰性能,缩短了步进电机驱动器的设计周期。     

压电陶瓷驱动器非线性的电源补偿研究

针对谐振型压电陶瓷驱动器的非线性,采用电压补偿法,设计并研究了一种由单片机控制的闭环反馈、修改、生成波形数据,开不生成驱动波形的数字化电源系统。实验表明,此电源系统能很好地对原始驱动波形进行修正,使驱动器相对原始驱动波形信号是一个线性系统。     

基于AVR单片机的无刷直流电机控制系统设计

根据永磁无刷直流电机控制系统的设计参数、成本及灵活性等各方面的要求,设计了以AVR单片机及LM621集成驱动器为核心的硬件平台.本控制系统保护功能较完善,硬件结构简单,成本较低,在实际工程中有一定的应用价值.     

串行显示驱动器PS7219及在单片机系统中的应用*

介绍了一种静态显示驱动器PS7219芯片的工作原理,给出了一个适于单片机的结构简单且十分复用的静态显示系统,并以89C51单片机为例,讨论了硬件连接和软件编程。     

24 V直流电机控制系统的设计

在PWM直流调速原理的基础上,设计了一种基于PIC16F690单片机和MOSFET的24 V直流无刷电机驱动器。介绍了以PIC16F690单片机为核心的控制系统实现方法,给出了设计的总体框图,部分硬件电路和控制软件流程图。该驱动器现已投入生产,经实际应用表明,该设计具有结构简单、精确、高效等特点,能够满足实际工程应用的要求。     

Achieving zT > 1 in Inexpensive Zintl Phase Ca9Zn4+xSb9 by Phase Boundary Mapping

Complex multinary compounds (ternary, quaternary, and higher) offer countless opportunities for discovering new semiconductors for applications such as photovoltaics and thermoelectrics. However, controlling doping has been a major challenge in complex semiconductors as there are many possibilities for charged intrinsic defects (e.g., vacancies, interstitials, antisite defects) whose energy depends on competing impurity phases. Even in compounds with no apparent deviation from a stoichiometric nominal composition, such defects commonly lead to free carrier concentrations in excess of 10²⁰ cm^?3. Nevertheless, by slightly altering the nominal composition, these defect concentrations can be tuned with small variation of the chemical potentials (composition) of each element. While the variation of chemical composition is undetectable, it is shown that the changes can be inferred by mapping (in nominal composition space) the boundaries where different competing impurity phases form. In the inexpensive Zintl compound Ca₉Zn_4+x Sb₉, the carrier concentrations can be finely tuned within three different three‐phase regions by altering the nominal composition (x = 0.2–0.8), enabling the doubling of thermoelectric performance (zT). Because of the low thermal conductivity, the zT can reach as high as 1.1 at 875 K, which is one of the highest among the earth abundant p‐type thermoelectrics with no ion conducting.     

基于AL9V576的MEPG1/2/4视频光纤传输系统

介绍了数字视频压缩的优点,提出了一种基于AL9V576的MPEG1/2/4视频光纤传输方式.     

贝多芬交响曲全集

去年我就获悉,“普罗”即将陆续引进推出具有国际水准与品味,而且售价仅20多元一张的现场音乐会系列DVD产品。在我的记忆里,这还是国内影音艺术产品中的开创之作。“普罗”为填补国内这一出版发行空白令人欣喜。新年伊始,我竟获得了“普罗”这个系列的十多款DVD,让我“饱餐”了一场高     

A 9-ns 1-Mbit CMOS SRAM

A 1-Mbit CMOS static RAM (SRAM) with a typical address access time of 9 ns has been developed. A high-speed sense amplifier circuit, consisting of a three-stage PMOS cross-coupled sense amplifier with a CMOS preamplifier, is the key to the fast access time. A parallel-word-access redundancy architecture, which causes no access time penalty, was also incorporated. A polysilicon PMOS load memory cell, which had a large on-current-to-off-current ratio, gave a much lower soft-error rate than a conventional high-resistance polysilicon load cell. The 1-Mbit SRAM, fabricated using a half-micrometer, triple-poly, and double-metal CMOS technology, operated at a single supply voltage of 5 V. An on-chip power supply converter was incorporated in the SRAM to supply a partial internal supply voltage of 4 V to the high-performance half-micrometer MOS transistors.<>     

1-V 9-bit pipelined switched-opamp ADC

A 9-bit 1.0-V pipelined analog-to-digital converter has been designed using the switched-opamp technique. The developed low-voltage circuit blocks are a multiplying analog-to-digital converter (MADC), an improved common-mode feedback circuit for a switched opamp, and a fully differential comparator. The input signal for the converter is brought in using a novel passive interface circuit. The prototype chip, implemented in a 0.5-μm CMOS technology, has differential nonlinearity and integral nonlinearity of 0.6 and 0.9 LSB, respectively, and achieves 50.0-dB SNDR at 5-MHz clock rate. As the supply voltage is raised to 1.5 V, the clock frequency can be increased to 14 MHz. The power consumption from a 1.0-V supply is 1.6 mW     

A 4-9 GHz 10 W wideband power amplifier

A 4-9 GHz wideband high power amplifier is designed and fabricated, which has demonstrated saturated output power of 10 W covering 6-8 GHz band, and above 6 W over the other band. This PA module uses a bal-ance configuration, and presents power gain of 7.3 ± 0.9 dB over the whole 4-9 GHz band and 39% power-added efficiency (PAE) at 8 GHz. Both the input and output VSWR are also excellent, which are bellow -10 dB.     

4B9--High resolution spectroscopy by Zeeman-tuned infrared laser

We have designed a Zeeman-tuned laser oscillating at nearly all laser transitions between 3 and 9 μm, and we have studied absorption bands between 1250 and 1450 cm^-1where many xenon and neon laser lines have sufficient gain to allow displacements of 0.1 cm^-1The apparatus is an internal-mirror discharge, dc excited, on a granite bench well isolated from mechanical vibrations. The Fabry-Perot cavity is 1.66 meter. Applied axial magnetic fields vary from 0 to 1800 Gs. The circular polarizations are converted to linear perpendicular polarizations by a quarter-wave plate consisting of a Fresnel prism. The laser beam, after passage through the absorption cell, is detected by a Ge-Au cell behind a monochromator. The detected signal and the magnetic field are simultaneously recorded by anXYrecorder.     

A 4–9 GHz 10W wideband power amplifier

A 4-9 GHz wideband high power amplifier is designed and fabricated, which has demonstrated saturated output power of 10 W covering 6-8 GHz band, and above 6 W over the other band. This PA module uses a balance configuration, and presents power gain of 7.3 ＋ 0.9 dB over the whole 4-9 GHz band and 39% power-added efficiency （PAE） at 8 GHz. Both the input and output VSWR are also excellent, which are bellow -10 dB.     

AM1x：Sitara ARM9微处理器

T1推出4款提供多种集成型连接选项的全新Sitara ARM9微处理器（MPU）与相应的评估板（EVM），可为嵌入式工业、医疗以及消费类设计开发人员提供支持各种特定行业外设与接口的高灵活架构，从而可满足这些市场不断发展的需求。