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.
上傳時間： 2013-11-02
上傳用戶：名爵少年
Easy-to-use and compact point-of-load power suppliesare necessary in systems with widely distributed, highcurrent, low voltage loads. The LTC®3415 provides acompact, simple and versatile solution. It includes a pairof integrated complementary power MOSFETs (32mΩtop and 25mΩ bottom) and requires no external senseresistor. A complete design requires an inductor andinput/output capacitors, and that’s it. The result is a fast,constant frequency, 7A current mode DC/DC switchingregulator.
標(biāo)簽： 387 DN 級聯(lián) 負(fù)載
上傳時間： 2013-10-18
上傳用戶：avensy
The LTC®3610 is a high power monolithic synchronousstep-down DC/DC regulator that can deliver up to 12Aof continuous output current from a 4V to 24V (28Vmaximum) input supply. It is a member of a high currentmonolithic regulator family (see Table 1) that featuresintegrated low RDS(ON) N-channel top and bottomMOSFETs. This results in a high effi ciency and highpower density solution with few external components.This regulator family uses a constant on-time valleycurrent mode architecture that is capable of operatingat very low duty cycles at high frequency and with veryfast transient response. All are available in low profi le(0.9mm max) QFN packages.
上傳時間： 2013-11-07
上傳用戶：moerwang
Telecommunication, satellite links and set-top boxes allrequire tuning a high frequency oscillator. The actualtuning element is a varactor diode, a 2-terminal device thatchanges capacitance as a function of reverse bias voltage.1 The oscillator is part of a frequency synthesizingloop, as detailed in Figure 1. A phase locked loop (PLL)compares a divided down representation of the oscillatorwith a frequency reference. The PLL’s output is levelshifted to provide the high voltage necessary to bias thevaractor, which closes a feedback loop by voltage tuningthe oscillator. This loop forces the voltage controlledoscillator (VCO) to operate at a frequency determined bythe frequency reference and the divider’s division ratio.
標(biāo)簽： 開關(guān)穩(wěn)壓器 低噪聲 上傳時間： 2013-12-20
上傳用戶：ABCDE
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
標(biāo)簽： DCDC 高電壓 低噪音 轉(zhuǎn)換器
上傳時間： 2013-10-28
上傳用戶：lhw888
In August of 1992 LTC published Application Note 49, “Illumination Circuitry for Liquid Crystal Displays.” One notable aspect of this event is that it generated more response than all previous LTC application notes combined. This level of interest, along with significant performance advances since AN-49’s appearance, justifies further discussion of LCD backlighting circuitry.
上傳時間： 2013-11-19
上傳用戶：lanjisu111
為解決直流逆變交流的問題，有效地利用能源，讓電源輸出最大功率，設(shè)計了高性能的基于IR2101最大功率跟蹤逆變器，并以SPMC75F2413A單片機作為主控制器。高電壓、高速功率的MOSFET或IGBT驅(qū)動器IR2101采用高度集成的電平轉(zhuǎn)換技術(shù)，同時上管采用外部自舉電容上電，能夠穩(wěn)定高效地驅(qū)動MOS管。該逆變器可以實現(xiàn)DC/AC的轉(zhuǎn)換，最大功率點的跟蹤等功能。實際測試結(jié)果表明，該逆變器系統(tǒng)具有跟蹤能力強，穩(wěn)定性高，反應(yīng)靈敏等特點，該逆變器不僅可應(yīng)用于普通的電源逆變系統(tǒng)，而且可應(yīng)用于光伏并網(wǎng)發(fā)電的逆變系統(tǒng)，具有廣泛的市場前景。 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
上傳時間： 2013-11-17
上傳用戶：lliuhhui
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.
上傳時間： 2013-10-12
上傳用戶：司令部正軍級
為解決我國水位監(jiān)測野外條件下長期無人看守的問題，研制開發(fā)了基于MSP430單片機的智能水位計。從其組成到各功能分別進(jìn)行了詳細(xì)的介紹，該智能水位計不僅實現(xiàn)了水位數(shù)據(jù)的實時監(jiān)測、記錄和定期采集等多種工作模式，而且提高了水位監(jiān)測精度，實現(xiàn)了水位監(jiān)測的智能化。 Abstract: In order to solve the problems of long-term unmanned observation in the field water monitoring，an intelligence water-level meter based on MSP430 is developed composition and every function moduce of the water level meter was introduced in detail. It not only realizes water level data collection and storage， regularly gathering and so on， but also improves the water-level precision ， finally realizes the intelligence.
上傳時間： 2013-11-17
上傳用戶：417313137
為了使音頻信號分析儀小巧可靠，成本低廉，設(shè)計了以2片MSP430F1611單片機為核心的系統(tǒng)。該系統(tǒng)將音頻信號送入八階巴特沃茲低通濾波器，對信號進(jìn)行限幅放大、衰減、電平位移、緩沖，并利用一單片機負(fù)責(zé)對前級處理后的模擬信號進(jìn)行采樣，將采集得到的音頻信號進(jìn)行4 096點基2的FFT計算，并對信號加窗函數(shù)提高分辨率，另一單片機負(fù)責(zé)對信號的分析及控制顯示設(shè)備。此設(shè)計精確的測量了音頻信號的功率譜、周期性、失真度指標(biāo)，達(dá)到較高的頻率分辨率，并能將測量結(jié)果通過紅外遙控器顯示在液晶屏上。 Abstract: o make the audio signal analyzer cheaper， smaller and more reliable， this system sends the audio signal to the eight-order butterworth filter， and then amplifies， attenuates， buffers it in a limiting range， transfers the voltage level of the signal before utilizing two MSP430F1611 MCU to realize the audio analysis. One is charged for sampling and dealing with the processed audio signal collected by the 4096 point radix-2 FFT calculation and imposes the window function to improve the frequency resolution. The other one controls the display and realizes the spectrum， periodicity， power distortion analysis in high resolution which is displayed in the LCD screen through the infrared remote control.
上傳時間： 2013-12-11
上傳用戶：jasonheung
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