Abstract: Using a wafer-level package (WLP) can reduce the overall size and cost of your solution.However when using a WLP IC, the printed circuit board (PCB) layout can become more complex and, ifnot carefully planned, result in an unreliable design. This article presents some PCB designconsiderations and general recommendations for choosing a 0.4mm- or 0.5mm-pitch WLP for yourapplication.
標簽： Considerations Guidelines and Design
上傳時間： 2013-10-14
上傳用戶：ysystc699
數字與模擬電路設計技巧IC與LSI的功能大幅提升使得高壓電路與電力電路除外，幾乎所有的電路都是由半導體組件所構成，雖然半導體組件高速、高頻化時會有EMI的困擾，不過為了充分發揮半導體組件應有的性能，電路板設計與封裝技術仍具有決定性的影響。 模擬與數字技術的融合由于IC與LSI半導體本身的高速化，同時為了使機器達到正常動作的目的，因此技術上的跨越競爭越來越激烈。雖然構成系統的電路未必有clock設計，但是毫無疑問的是系統的可靠度是建立在電子組件的選用、封裝技術、電路設計與成本，以及如何防止噪訊的產生與噪訊外漏等綜合考慮。機器小型化、高速化、多功能化使得低頻/高頻、大功率信號/小功率信號、高輸出阻抗/低輸出阻抗、大電流/小電流、模擬/數字電路，經常出現在同一個高封裝密度電路板，設計者身處如此的環境必需面對前所未有的設計思維挑戰，例如高穩定性電路與吵雜(noisy)性電路為鄰時，如果未將噪訊入侵高穩定性電路的對策視為設計重點，事后反復的設計變更往往成為無解的夢魘。模擬電路與高速數字電路混合設計也是如此，假設微小模擬信號增幅后再將full scale 5V的模擬信號，利用10bit A/D轉換器轉換成數字信號，由于分割幅寬祇有4.9mV，因此要正確讀取該電壓level并非易事，結果造成10bit以上的A/D轉換器面臨無法順利運作的窘境。另一典型實例是使用示波器量測某數字電路基板兩點相隔10cm的ground電位，理論上ground電位應該是零，然而實際上卻可觀測到4.9mV數倍甚至數十倍的脈沖噪訊(pulse noise)，如果該電位差是由模擬與數字混合電路的grand所造成的話，要測得4.9 mV的信號根本是不可能的事情，也就是說為了使模擬與數字混合電路順利動作，必需在封裝與電路設計有相對的對策，尤其是數字電路switching時，ground vance noise不會入侵analogue ground的防護對策，同時還需充分檢討各電路產生的電流回路(route)與電流大小，依此結果排除各種可能的干擾因素。以上介紹的實例都是設計模擬與數字混合電路時經常遇到的瓶頸，如果是設計12bit以上A/D轉換器時，它的困難度會更加復雜。
上傳時間： 2013-11-16
上傳用戶：731140412
Abstract: Some power architectures require the power supply sequencer (or system manager) to controldownstream power MOSFETs to allow power to flow into branch circuits. This application note explains howsystem power sequencing and level shifting can be accomplished using a low-voltage system manager
上傳時間： 2013-11-02
上傳用戶：wys0120
Abstract: Some types of loads require more current during startup than when running. Other loads can be limited to a lower-powercurrent during startup but require a higher operating current. This article describes an application circuit that automatically adjusts apower circuit’s overcurrent protection level up or down after startup is complete.
上傳時間： 2013-10-23
上傳用戶：swaylong
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
Abstract: In battery-powered RF transmitters such as garage door openers and remote keyless entry for cars, as the battery drains,
上傳時間： 2013-10-23
上傳用戶：nanxia
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驅動器IR2101采用高度集成的電平轉換技術，同時上管采用外部自舉電容上電，能夠穩定高效地驅動MOS管。該逆變器可以實現DC/AC的轉換，最大功率點的跟蹤等功能。實際測試結果表明，該逆變器系統具有跟蹤能力強，穩定性高，反應靈敏等特點，該逆變器不僅可應用于普通的電源逆變系統，而且可應用于光伏并網發電的逆變系統，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
