Abstract: Field-programmable gate arrays (FPGAs) are used in a wide variety of applications and end markets, including digital signalprocessing, medical imaging, and high-performance computing. This application note outlines the issues related to powering FPGAs.It also discusses Maxim's solutions for powering Altera® FPGAs.
高的工作電壓高達(dá)100V N雙N溝道MOSFET同步驅(qū)動 The D810DCDC is a synchronous step-down switching regulator controller that can directly step-down voltages from up to 100V, making it ideal for telecom and automotive applications. The D810DCDC uses a constant on-time valley current control architecture to deliver very low duty cycles with accurate cycle-by-cycle current limit, without requiring a sense resistor. A precise internal reference provides 0.5% DC accuracy. A high bandwidth (25MHz) error amplifi er provides very fast line and load transient response. Large 1Ω gate drivers allow the D810DCDC to drive multiple MOSFETs for higher current applications. The operating frequency is selected by an external resistor and is compensated for variations in VIN and can also be synchronized to an external clock for switching-noise sensitive applications. Integrated bias control generates gate drive power from the input supply during start-up and when an output shortcircuit occurs, with the addition of a small external SOT23 MOSFET. When in regulation, power is derived from the output for higher effi ciency.
The MAX14885E, a 2:2 VGA switch, connects a VGA source to a VGA monitor. To ease direct connection to graphics controllers orthe ASIC, the MAX14885E has two supplies: VCC, a 5V ±5% supply, drives the VGA side interface; and the VL supply sets the logicswitching thresholds on the digital input pins (EN, S00, S01, S10, S11, SHA, SHB, SVA, and SVB). This application note documentsthe proper sequencing of the VCC and VL power supplies on power-up.
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
In predominantly digital systems it is often necessaryto include linear circuit functions. Traditionally, separatepower supplies have been used to run the linear components(see Box, “Linear Power Supplies—Past, Present,and Future”).
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畢業(yè)設(shè)計 USB TO Gigabit LAN 網(wǎng)卡 隨著網(wǎng)絡(luò)技術(shù)飛速發(fā)展，多媒體的應(yīng)用越來越多，人們對網(wǎng)絡(luò)的要求也越來越高，為了適應(yīng)市場的需求，網(wǎng)卡出現(xiàn)了。它以其結(jié)構(gòu)簡單、成本低廉、兼容性強(qiáng)等諸多的優(yōu)越性得到了廣泛的應(yīng)用。由于網(wǎng)絡(luò)的應(yīng)用越來越廣泛，網(wǎng)卡的應(yīng)用也越來越多、功能越來越強(qiáng)大。開始時由于技術(shù)方面的限制，網(wǎng)卡只有10Mbps的吞吐量，由于網(wǎng)絡(luò)技術(shù)的發(fā)展，100Mbps吞吐量的網(wǎng)卡開始在市場上得到廣泛的應(yīng)用。而現(xiàn)在1000Mbps吞吐量的網(wǎng)卡的出現(xiàn)又給網(wǎng)絡(luò)的傳輸帶來了新的活力。 論文中主要闡述了基于以太網(wǎng)的USB TO Gigabit LAN網(wǎng)卡的設(shè)計與制作。論文首先對以太網(wǎng)進(jìn)行了介紹，緊接著講了網(wǎng)卡的基本知識。隨后又對USB TO Gigabit LAN網(wǎng)卡的電路設(shè)計和制作進(jìn)行了詳細(xì)的描述。論文還包括了USB TO Gigabit LAN網(wǎng)卡的調(diào)試等內(nèi)容。
Analog Inputs and Outputs in an S7 PLC are represented in the PLC as a 16-bit integer. Over
the nominal span of the analog input or output, the value of this integer will range between -
27648 and +27648. However, it is easier to use the analog values if they are scaled to the
same units and ranges as the process being controlled. This applications tip describes
methods for scaling analog values to and from engineering units.
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)到控制異步電動機(jī)轉(zhuǎn)速的目的。實(shí)驗結(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.
