Linear Technology offers a variety of devices that simplifyconverting power from a USB cable, but the LTC®3455represents the highest level of functional integration yet. The LTC3455 seamlessly manages power flowbetween an AC adapter, USB cable and Li-ion battery,while complying with USB power standards, all from a4mm × 4mm QFN package. In addtion, two high efficiencysynchronous buck converters GeneRate low voltage railswhich most USB-powered peripherals require. TheLTC3455 also provides power-on reset signals for themicroprocessor, a Hot SwapTM output for poweringmemory cards as well as an uncommitted gain blocksuitable for use as a low-battery comparator or an LDOcontroller. The PCB real estate required for the entire USBpower control circuit and two DC/DC converters is only225mm2.
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
ØCPV is the abbreviation of concentration PV.
Ø It utilizes optics to concentrate the sunlight to the CPV cell to GeneRate power.
Ø The purpose of CPV is to reduce the cell’s area and the cost of PV module.
數(shù)字控制的交流調(diào)速系統(tǒng)所選用的微處理器、功率器件及產(chǎn)生PWM波的方法是影響交流調(diào)速系統(tǒng)性能好壞的直接因素。在介紹了正弦脈寬調(diào)制(SPWM)技術(shù)的基礎(chǔ)上,設(shè)計(jì)了一種以8098單片機(jī)作為控制器,以智能功率模塊IPM為開關(guān)器件的變頻調(diào)速系統(tǒng)。通過軟件編程,產(chǎn)生正弦脈沖寬度調(diào)制波形來控制絕緣柵雙極晶體管的導(dǎo)通和關(guān)斷,從而達(dá)到控制異步電動(dòng)機(jī)轉(zhuǎn)速的目的。實(shí)驗(yàn)結(jié)果表明,該系統(tǒng)可調(diào)頻率調(diào)電壓,穩(wěn)定度高,調(diào)速范圍寬,具有較強(qiáng)的實(shí)用價(jià)值
Abstract:
AC variable speed with digital control systems used microprocessors, power devices and GeneRate PWM wave is the direct factors of affecting the performance AC speed regulation system. On the basis of introducing the sinusoidal pulse width modulation (SPWM) technology,this paper designed variable speed system which used 8098 as a controller, intelligent power module IPM as switching device. Through software programming, resulting in sinusoidal pulse width modulation waveform to control the insulated gate bipolar transistor turn on and off, so as to achieve the purpose of speed control of induction motors. Experimental results show that the system can adjust frequency modulation voltage, high stability, wide speed range, has a strong practical value.
為解決電致變色器件的顏色變化受外界環(huán)境顏色控制的問題,設(shè)計(jì)了一種基于單片機(jī)的便攜式顏色自適應(yīng)識(shí)別電路。與傳統(tǒng)顏色識(shí)別電路相比較,該電路利用數(shù)字式的顏色傳感器來獲取外界環(huán)境顏色,產(chǎn)生的數(shù)字顏色信號易于單片機(jī)進(jìn)行處理。在電路中,下位機(jī)部分主要負(fù)責(zé)獲取電致變色器件變色參數(shù)及控制電致變色器件的顏色變化;而上位機(jī)部分主要負(fù)責(zé)把下位機(jī)獲取的電致變色器件變色參數(shù)進(jìn)行電壓到顏色的曲線擬合,并通過藍(lán)牙通信把擬合曲線參數(shù)傳遞給下位機(jī)。結(jié)果表明,該電路能自動(dòng)根據(jù)環(huán)境顏色提供-4~4 V范圍步進(jìn)為0.1 V的電壓來驅(qū)動(dòng)電致變色器件的顏色顯示,與傳統(tǒng)的顏色識(shí)別電路設(shè)計(jì)相比,識(shí)別的精度和速度都得到了明顯改善。
Abstract:
In this paper, a portable adaptive circuit for color identification(PACCI) based on MCU was designed. Compared to the traditional color identification circuit, the PACCI adopts digital sensor to detect the color data from external environment and further GeneRate digital color data, which can be processed easily by MCU. In PACCI, the slave is mainly responsible for detecting the color parameters of the corresponding elcreochromic device and further driving it. For the master, which is mainly responsible for the color curve fitting based on the parameters of the electrochromic device, and transmits the fitting parameters to the slave through the bluetooth device. The results show that the PACCI can provide the basis voltage range from -4V to 4V automatically based on the colors of external environment with step as 0.1V to drive the corresponding electrochromic device. Compared to the traditional color recognition circuit, the recognition accuracy and speed of PACCI have been improved significantly.
介紹了采用ATmega48單片機(jī)實(shí)現(xiàn)三相無刷直流電機(jī)控制器的方法。利用Atmega48獲得帶死區(qū)的脈寬調(diào)制(PWM)、霍爾傳感器的換相處理、正弦驅(qū)動(dòng)信號的產(chǎn)生和電機(jī)轉(zhuǎn)速的控制等功能。采用該方法的優(yōu)點(diǎn)是所需的外圍器件少,成本低。
Abstract:
The method of 3-phase brushless DC motor control based on ATmega48 is presented in this paper.The system uses ATmega48 to GeneRate PWM signals with dead-time, hall sensors signals commutation,sine driving signal and rotational speed of motor.Using this method,the needed external devices are few, the cost is low.
為解決傳統(tǒng)可視倒車?yán)走_(dá)視頻字符疊加器結(jié)構(gòu)復(fù)雜,可靠性差,成本高昂等問題,在可視倒車?yán)走_(dá)設(shè)計(jì)中采用視頻字符發(fā)生器芯片MAX7456。該芯片集成了所有用于產(chǎn)生用戶定義OSD,并將其插入視頻信號中所需的全部功能,僅需少量的外圍阻容元件即可正常工作。給出了以MAX7456為核心的可視倒車?yán)走_(dá)的軟、硬件實(shí)現(xiàn)方案及設(shè)計(jì)實(shí)例。該方案具有電路結(jié)構(gòu)簡單、價(jià)格低廉、符合人體視覺習(xí)慣的特點(diǎn)。經(jīng)實(shí)際裝車測試,按該方案設(shè)計(jì)的可視倒車?yán)走_(dá)視場清晰、提示字符醒目、工作可靠,可有效降低駕駛員倒車時(shí)的工作強(qiáng)度、減少倒車事故的發(fā)生。
Abstract:
A new video and text generation chip,MAX7456,was used in the design of video parking sensor in order to simplify system structure,improve reliability and reduce cost. This chip included all the necessary functions to GeneRate user-defined OSDs and to add them into the video signals. It could be put into work with addition of just a small number of resistances and capacitors. This paper provided software and hardware implementation solutions and design example based on the chip. The system had the characteristics of simplicity in circuit structure,lower cost,and comfort for the nature of human vision. Loading road test demonstrates high video and text display quality and reliable performance,which makes the driver easy to see backward and reduces chance of accidents.
Internal Interrupts are used to respond to asynchronous requests from a certain part of themicrocontroller that needs to be serviced. Each peripheral in the TriCore as well as theBus Control Unit, the Debug Unit, the Peripheral Control Processor (PCP) and the CPUitself can GeneRate an Interrupt Request.So what is an external Interrupt?An external Interrupt is something alike as the internal Interrupt. The difference is that anexternal Interrupt request is caused by an external event. Normally this would be a pulseon Port0 or Port1, but it can be even a signal from the input buffer of the SSC, indicatingthat a service is requested.The User’s Manual does not explain this aspect in detail so this ApNote will explain themost common form of an external Interrupt request. This ApNote will show that there is aneasy way to react on a pulse on Port0 or Port1 and to create with this impulse an InterruptService Request. Later in the second part of the document, you can find hints on how todebounce impulses to enable the use of a simple switch as the input device.Note: You will find additional information on how to setup the Interrupt System in theApNote “First steps through the TriCore Interrupt System” (AP3222xx)1. It would gobeyond the scope of this document to explain this here, but you will find selfexplanatoryexamples later on.
Abstract: Many industrial/scientific/medical (ISM) band radio frequency (RF) receivers use an external Sallen-Key datafilter and a data slicer to GeneRate the baseband digital output. This tutorial describes the ISM-RF Baseband Calculator,which can be used to calculate the filter capacitor values and the data slicer RC components, while providing a visualexample of the baseband signals.