Once relegated to the hinterlands of low cost indicatorlights, the LED is again in the spotlight of the lightingworld. LED lighting is now ubiquitous, from car headlightsto USB-powered lava lamps. Car headlights exemplifyapplications that capitalize on the LED’s clear advantages—unwavering high quality light output, tough-assteelrobustness, inherent high effi ciency—while a USBlava lamp exemplifi es applications where only LEDs work.Despite these clear advantages, their requirement forregulated voltage and current make LED driver circuitsmore complex than the venerable light bulb, but some newdevices are closing the gap. For instance, the LTM®8040μModule™ LED driver integrates all the driver circuitryinto a single package, allowing designers to refocus theirtime and effort on the details of lighting design criticalto a product’s success.
上传时间： 2013-10-16
上传用户：togetsomething
An essential component of a noise-free audio device isa clean power supply, but few switching regulators canoperate at high efficiency while keeping the switchingfrequency out of the audio band. The LTC®3620 fills thisvoid. It is a high efficiency 15mA buck regulator with aprogrammable minimum switching frequency, making itpossible to virtually eliminate audible switching noise. Theinternal synchronous switches and low quiescent currentof this buck regulator provide the ability to maintain highefficiency, while its small footprint makes it ideal for tiny,low power audio applications.
上传时间： 2013-10-21
上传用户：非衣2016
A recent trend in the design of portable devices has beento use ceramic capacitors to filter DC/DC converter inputs.Ceramic capacitors are often chosen because of theirsmall size, low equivalent series resistance (ESR) and highRMS current capability. Also, recently, designers havebeen looking to ceramic capacitors due to shortages oftantalum capacitors.
上传时间： 2013-11-05
上传用户：comer1123
Photomultipliers (PMT), avalanche photodiodes (APD),ultrasonic transducers, capacitance microphones, radiationdetectors and similar devices require high voltage,low current bias. Additionally, the high voltage must bepristinely free of noise; well under a millivolt is a commonrequirement with a few hundred microvolts sometimesnecessary. Normally, switching regulator confi gurationscannot achieve this performance level without employingspecial techniques. One aid to achieving low noise is thatload currents rarely exceed 5mA. This freedom permitsoutput fi ltering methods that are usually impractical
上传时间： 2013-10-28
上传用户：lhw888
In an increasing trend, telecommunications, networking,audio and instrumentation require low noise power supplies.In particular, there is interest in low noise, lowdropout linear regulators (LDO). These components powernoise-sensitive circuitry, circuitry that contains noisesensitiveelements or both. Additionally, to conserve power,particularly in battery driven apparatus such as cellulartelephones, the regulators must operate with low input-tooutputvoltages.1 Devices presently becoming availablemeet these requirements (see separate section, “A Familyof 20mVRMS Noise, Low Dropout Regulators”).
上传时间： 2013-10-30
上传用户：yeling1919
为解决直流逆变交流的问题，有效地利用能源，让电源输出最大功率，设计了高性能的基于IR2101最大功率跟踪逆变器，并以SPMC75F2413A单片机作为主控制器。高电压、高速功率的MOSFET或IGBT驱动器IR2101采用高度集成的电平转换技术，同时上管采用外部自举电容上电，能够稳定高效地驱动MOS管。该逆变器可以实现DC/AC的转换，最大功率点的跟踪等功能。实际测试结果表明，该逆变器系统具有跟踪能力强，稳定性高，反应灵敏等特点，该逆变器不仅可应用于普通的电源逆变系统，而且可应用于光伏并网发电的逆变系统，具有广泛的市场前景。 Abstract: To solve the problem of DC-AC inverter， and to utilize solar energy more efficiently， the design of maximum power point tracking inverter based on IR2101 was achieved with a high-performance， which can make the system output power maximum. SPMC75F2413A was adopted as main controller. IR2101 is a high voltage， high speed power MOSFET and IGBT driver. It adopted highly integrated voltage level transforming technology， and an external bootstrap capacitor was used， which could drive MOS tube efficiently and stably. Many functions are achieved in the system， such as DC/AC conversion， maximun power point tracking， etc. The actual test result shows that the inverter system has characteristics of strong tracking ability， high stability and reacting quickly. The design can not only be used in ordinary power inverter system， but also be used in photovoltaic power inverter system. The design has certain marketing prospects
上传时间： 2013-11-17
上传用户：lliuhhui
Features: High efficiency, high reliability, low cost AC input range selected by switch 100% full load burn-in test Protections: Short circuit / Over load Fixed switching frequency at 25KHz Cooling by free air convection 1 year warranty Dimensions: 199*98*38mm (L*W*H)
标签： Switchin Output Single SKS
上传时间： 2013-10-30
上传用户：taa123456
The P89LPC912/913/914 are single-chip microcontrollers in low-cost 14-pin packages, based on a high performance processor architecture that executes instructions in two to four clocks, six times the rate of standard 80C51 devices. Many system level functions have been incorporated into the P89LPC912/913/914 in order to reduce component count, board space, and system cost.
上传时间： 2013-10-12
上传用户：司令部正军级
数字控制的交流调速系统所选用的微处理器、功率器件及产生PWM波的方法是影响交流调速系统性能好坏的直接因素。在介绍了正弦脉宽调制(SPWM)技术的基础上，设计了一种以8098单片机作为控制器，以智能功率模块IPM为开关器件的变频调速系统。通过软件编程，产生正弦脉冲宽度调制波形来控制绝缘栅双极晶体管的导通和关断，从而达到控制异步电动机转速的目的。实验结果表明，该系统可调频率调电压，稳定度高，调速范围宽，具有较强的实用价值 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.
上传时间： 2013-11-14
上传用户：ynwbosss
HIGH SPEED 8051 μC CORE - Pipe-lined Instruction Architecture; Executes 70% of Instructions in 1 or 2 System Clocks - Up to 25MIPS Throughput with 25MHz System Clock - 22 Vectored Interrupt Sources MEMORY - 4352 Bytes Internal Data RAM (256 + 4k) - 64k Bytes In-System Programmable FLASH Program Memory - External Parallel Data Memory Interface – up to 5Mbytes/sec DIGITAL PERIPHERALS - 64 Port I/O; All are 5V tolerant - Hardware SMBusTM (I2CTM Compatible), SPITM, and Two UART Serial Ports Available Concurrently - Programmable 16-bit Counter/Timer Array with 5 Capture/Compare Modules - 5 General Purpose 16-bit Counter/Timers - Dedicated Watch-Dog Timer; Bi-directional Reset CLOCK SOURCES - Internal Programmable Oscillator: 2-to-16MHz - External Oscillator: Crystal, RC, C, or Clock - Real-Time Clock Mode using Timer 3 or PCA SUPPLY VOLTAGE ........................ 2.7V to 3.6V - Typical Operating Current: 10mA @ 25MHz - Multiple Power Saving Sleep and Shutdown Modes 100-Pin TQFP (64-Pin Version Available) Temperature Range: –40°C to +85°C
标签： C8051F020
上传时间： 2013-10-12
上传用户：lalalal
