Piezoelectric motors are used in digital cameras for autofocus,zooming and optical image stabilization. Theyare relatively small, lightweight and effi cient, but theyalso require a complicated driving scheme. Traditionally,this challenge has been met with the use ofseparatecircuits, including a step-up converter and an oversizedgeneric full-bridge drive IC. The resulting high componentcount and large board space are Especially problematicin the design of cameras for ever shrinking cell phones.The LT®3572 solves these problems by combining astep-up regulator and a dual full-bridge driver in a 4mm× 4mm QFN package. Figure 1 shows a typical LT3572Piezo motor drive circuit. A step-up converter is usedto generate 30V from a low voltage power source suchas a Li-Ion battery or any input power source within thepart’s wide input voltage range of 2.7V to 10V. The highoutput voltage of the step-up converter, adjustable upto 40V, is available for the drivers at the VOUT pin. Thedrivers operate in a full-bridge fashion, where the OUTAand OUTB pins are the same polarity as the PWMA andPWMB pins, respectively, and the OUTA and OUTB pinsare inverted from PWMA and PWMB, respectively. Thestep-up converter and both Piezo drivers have their ownshutdown control. Figure 2 shows a typical layout
Today’s computer, datacom, and telecom systems demandpower supplies that are effi cient, respond quicklyto load transients and accurately regulate the voltageat the load. For example, load current can be measuredby using the inductor DCR, thus eliminating the needfor a dedicated sense resistor. Inductor DCR sensingincreases effi ciency—Especially at heavy load—whilereducing component cost and required board space.The LTC®3856 single-output 2-phase synchronous buckcontroller improves the accuracy of inductor DCR sensingby compensating for changes in DCR due to temperature.
針對(duì)目前汽車追尾事件頻發(fā)問題，提出一種防汽車車前和車后追尾的安全裝置設(shè)計(jì)。該設(shè)計(jì)以高性能、低功耗的8位AVR微處理器ATmega8L為核心，結(jié)合霍爾式車速傳感器、激光雷達(dá)測(cè)距裝置和MMA7260QT加速度傳感器，能夠兼顧車前和車后，摒棄以往設(shè)計(jì)中只考慮車前或車后單一性缺點(diǎn)，尤其適用于高速、夜晚或新手行車。
Abstract:
Aiming at the high frequency of vehicle rear-end collision，a safe device design of anti-vehicle rear-end collision is presented.In the design，the high-performance，low-power8-bit AVR microprocessor ATmega8L is utilized as a core combined with Hall-type speed sensor，laser-radar ranging devices and the acceleration sensor MMA7260QT.The design considers both the front and back of a car，and overcomes the drawbacks of former designs in which only the front or the back of the car is considered，so it is Especially suitable for high-speed，night or the beginner’s driving.
介紹了以AVR單片機(jī)ATmega16為核心，采用前端信號(hào)調(diào)理電路、程控增益放大器以及波形顯示LCD（GDM12864A）實(shí)現(xiàn)的一個(gè)簡(jiǎn)易示波器。并給出該系統(tǒng)設(shè)計(jì)的硬件和軟件設(shè)計(jì)方案。
Abstract:
Abstract:This paper introduces an easy digital storage oscilloscope based on the AVR microcontroller ATmega16,Especially emphasizes on the software design and the hardware design which contains signal processing circuit,gain-programmed amplifier circuit and LCD’s interface circuit and so on.
MMC/SD卡以其優(yōu)越的性能，在單片機(jī)嵌入式設(shè)備中得到廣泛應(yīng)用。將MMC/SD卡作為外部掉電存儲(chǔ)介質(zhì)應(yīng)用于音頻信號(hào)發(fā)生器中，通過8051F330單片機(jī)上的SPI接口，實(shí)現(xiàn)單片機(jī)—MMC/SD卡的存儲(chǔ)擴(kuò)展，設(shè)計(jì)了此硬件平臺(tái)上的MMC/SD卡的單片機(jī)驅(qū)動(dòng)程序，并給出了相應(yīng)的程序代碼，滿足音頻信號(hào)發(fā)生器的大容量存儲(chǔ)要求。
Abstract:
MMC/SD card is more and more widely used in the single chip embedded devices for their excellent performances.This article introduces the application of MMC/SD card as the external power down storage medium in audio signal generator. The extension technology Especially for storage of single chip-MMC/SD card via SPI interfaces in 8051F330 single chip, including designs single chip drive program of MMC/SD card based on hardware platform,and also gives the key coding of the program. The implementation of big capacity storage is meaningful in audio signal generator.
針對(duì)材料試驗(yàn)機(jī)等設(shè)備中要求測(cè)量或控制材料拉伸或壓縮的位移，一般采用光電軸角編碼器檢測(cè)位置信號(hào)，輸出正交編碼脈沖信號(hào)。若采用其他方法檢測(cè)位置信號(hào)，必然導(dǎo)致電路設(shè)計(jì)復(fù)雜，可靠性降低。因此，提出一種基于LS7266R1的電子式萬能材料試驗(yàn)機(jī)設(shè)計(jì)方案。給出了試驗(yàn)機(jī)中的控制器工作原理，LS7266R1與單片機(jī)的接口硬件設(shè)計(jì)，以及主程序軟件流程圖。巧妙地把力量傳感器，位移傳感器等機(jī)械運(yùn)動(dòng)狀態(tài)的壓力或拉力以及位置坐標(biāo)，變成了電壓信號(hào)和電脈沖數(shù)字信號(hào)，供A/D測(cè)量和LS7266R1計(jì)數(shù)，從而實(shí)現(xiàn)了獨(dú)立完成材料試驗(yàn)控制或通過PC機(jī)串口命令完成材料試驗(yàn)控制。
Abstract:
Aiming at the requirement that the displacement of the tension and compression always be tested and controlled in the equipement such as material testing machine. The position signal was tested by photoelectric axial angle coder. Therefore， the paper proposes the design of electronic universal testing machine design based on LS7266R1. If the position signal detected by other methods， will inevitably lead to the circuit design complexity， reliability decreased. The work theory of the controller， the hardware interface design between LS7266R1 and single chip， and the flow chart of main program， are presented in this paper. The signal of the compression or tension power and displacement at working， which tested by power sensor and displacement sensor Especially， is changed into electric voltage and electric pulse numerical signals. And these signals can be tested by A/D and counted by LS7266R1. Finally the test of the material properties can be controlled by itself， or controlled by the COM command of PC.
The P90CL301 is a highly integrated 16/32 bit micro-controller Especially suitable for applications requiring lowvoltage and low power consumption. It is fully software compatible with the 68000. Furthermore, it provides bothstandard as well as advanced peripheral functions on-chip.One of these peripheral functions is the I2C bus. This report describes worked-out driver software (written in C) toprogram the P90CL301 I2C interface. It also contains interface software routines offering the user a quick start inwriting a complete I2C system application.
Design techniques for electronic systems areconstantly changing. In industries at the heart of thedigital revolution, this change is Especially acute.Functional integration, dramatic increases incomplexity, new standards and protocols, costconstraints, and increased time-to-market pressureshave bolstered both the design challenges and theopportunities to develop modern electronic systems.One trend driving these changes is the increasedintegration of core logic with previously discretefunctions to achieve higher performance and morecompact board designs.
When I started writing the first edition of RF Power Amplifiers for Wireless Communications,some time back in 1997, it seemed that I was roaming a largely uninhabitedlandscape. For reasons still not clear to me there were few, if any, otherbooks dedicated to the subject of RF power amplifiers. Right at the same time, however,hundreds of engineers were being assigned projects to design PAs for wirelesscommunications products. It was not, therefore, Especially difficult to be successfulwith a book that was fortuitously at the right place and the right time.
同步技術(shù)是跳頻通信系統(tǒng)的關(guān)鍵技術(shù)之一，尤其是在快速跳頻通信系統(tǒng)中，常規(guī)跳頻通信通過同步字頭攜帶相關(guān)碼的方法來實(shí)現(xiàn)同步，但對(duì)于快跳頻來說，由于是一跳或者多跳傳輸一個(gè)調(diào)制符號(hào)，難以攜帶相關(guān)碼。對(duì)此引入雙跳頻圖案方法，提出了一種適用于快速跳頻通信系統(tǒng)的同步方案。采用短碼攜帶同步信息，克服了快速跳頻難以攜帶相關(guān)碼的困難。分析了同步性能，仿真結(jié)果表明該方案同步時(shí)間短、虛警概率低、捕獲概率高，同步性能可靠。
Abstract:
Synchronization is one of the key techniques to frequency-hopping communication system， Especially in the fast frequency hopping communication system. In conventional frequency hopping communication systems， synchronization can be achieved by synchronization-head which can be used to carry the synchronization information， but for the fast frequency hopping， Because modulation symbol is transmitted by per hop or multi-hop， it is difficult to carry the correlation code. For the limitation of fast frequency hopping in carrying correlation code， a fast frequency-hopping synchronization scheme with two hopping patterns is proposed. The synchronization information is carried by short code， which overcomes the difficulty of correlation code transmission in fast frequency-hopping. The performance of the scheme is analyzed， and simulation results show that the scheme has the advantages of shorter synchronization time， lower probability of false alarm， higher probability of capture and more reliable of synchronization.
