亚洲欧美第一页_禁久久精品乱码_粉嫩av一区二区三区免费野_久草精品视频

蟲蟲首頁| 資源下載| 資源專輯| 精品軟件
登錄| 注冊

deviCE-specific

  • 多層印制板設計基本要領

    【摘要】本文結合作者多年的印制板設計經驗,著重印制板的電氣性能,從印制板穩定性、可靠性方面,來討論多層印制板設計的基本要求。【關鍵詞】印制電路板;表面貼裝器件;高密度互連;通孔【Key words】Printed Circuit Board;Surface Mounting Device;High Density Interface;Via一.概述印制板(PCB-Printed Circuit Board)也叫印制電路板、印刷電路板。多層印制板,就是指兩層以上的印制板,它是由幾層絕緣基板上的連接導線和裝配焊接電子元件用的焊盤組成,既具有導通各層線路,又具有相互間絕緣的作用。隨著SMT(表面安裝技術)的不斷發展,以及新一代SMD(表面安裝器件)的不斷推出,如QFP、QFN、CSP、BGA(特別是MBGA),使電子產品更加智能化、小型化,因而推動了PCB工業技術的重大改革和進步。自1991年IBM公司首先成功開發出高密度多層板(SLC)以來,各國各大集團也相繼開發出各種各樣的高密度互連(HDI)微孔板。這些加工技術的迅猛發展,促使了PCB的設計已逐漸向多層、高密度布線的方向發展。多層印制板以其設計靈活、穩定可靠的電氣性能和優越的經濟性能,現已廣泛應用于電子產品的生產制造中。下面,作者以多年設計印制板的經驗,著重印制板的電氣性能,結合工藝要求,從印制板穩定性、可靠性方面,來談談多層制板設計的基本要領。

    標簽: 多層 印制板

    上傳時間: 2013-11-19

    上傳用戶:zczc

  • pci e PCB設計規范

    This document provides practical, common guidelines for incorporating PCI Express interconnect layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10- layer or more server baseboard designs. Guidelines and constraints in this document are intended for use on both baseboard and add-in card PCB designs. This includes interconnects between PCI Express devices located on the same baseboard (chip-to-chip routing) and interconnects between a PCI Express device located “down” on the baseboard and a device located “up” on an add-in card attached through a connector. This document is intended to cover all major components of the physical interconnect including design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card edge-finger and connector considerations. The intent of the guidelines and examples is to help ensure that good high-speed signal design practices are used and that the timing/jitter and loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect. However, while general physical guidelines and suggestions are given, they may not necessarily guarantee adequate performance of the interconnect for all layouts and implementations. Therefore, designers should consider modeling and simulation of the interconnect in order to ensure compliance to all applicable specifications. The document is composed of two main sections. The first section provides an overview of general topology and interconnect guidelines. The second section concentrates on physical layout constraints where bulleted items at the beginning of a topic highlight important constraints, while the narrative that follows offers additional insight.  

    標簽: pci PCB 設計規范

    上傳時間: 2013-10-15

    上傳用戶:busterman

  • 基于USB HID類數據通信的直流電源監控設計

    為了實現直流電源的監控,提出了一種具有USB HID數據通信功能的直流電源設計方案。詳細論述了基于STM32 USB固件庫(USB-FS Device library V3.3)的自定義HID類下位機的實現,介紹了如何在VC2010集成開發環境中編寫多線程上位機程序并運用PlotLab(一個快速信號繪圖和可視化的VCL組件)顯示實時波形,最后再以實驗開發板和PC實現了HID數據通信,證明了此監控設計方案的可行性。

    標簽: USB HID 數據通信 直流電源

    上傳時間: 2013-10-17

    上傳用戶:13162218709

  • LED的電源管理

    A light-emitting diode (LED) is a semiconductor device that emits narrow-spectrum incoherent light when forward-biased.The color of the emitted light depends on the chemical composition of the semiconductor material used, and can benear-ultraviolet, visible or infrared. LEDs are more prevalent today than ever before, replacing traditional incandescent andfluorescent bulbs in many lighting applications. Incandescents use a heated filament, are subject to breakage and burnoutand operate at a luminous efficiency of 2% to 4%. Fluorescents are more efficient, at 7% to 12%, but require highdrive voltage and contain mercury, a toxic substance that may be eventually banned in certain countries. LEDs, however,produce light directly through electroluminescence, operate at low voltage and can deliver over 20% luminous efficiency.

    標簽: LED 電源管理

    上傳時間: 2013-11-07

    上傳用戶:xiaoyuer

  • CN3052A(鋰離子電池充電器)

    The CN3052A is a complete constant-current /constant voltage linear charger for single cell Li-ion and Li Polymer rechargeable batteries. The device contains an on-chip power MOSFET and eliminates the need for the external sense resistor and blocking diode.

    標簽: 3052A 3052 CN 鋰離子電池

    上傳時間: 2013-11-10

    上傳用戶:子虛烏有

  • VCC_VDD_VSS之間的區別

    VCC:C=circuit 表示電路的意思, 即接入電路的電壓; VDD:D=device 表示器件的意思, 即器件內部的工作電壓; VSS:S=series 表示公共連接的意思,通常指電路公共接地端電壓.

    標簽: VCC_VDD_VSS

    上傳時間: 2013-11-22

    上傳用戶:squershop

  • PCI Express電源解決方案

      PCI ExpressTM is the third generation of PCI (PeripheralComponent Interconnect) technology used to connect I/Operhipheral devices in computer systems. It is intended asa general purpose I/O device interconnect that meets theneeds of a wide variety of computing platforms such asdesktop, mobile, server and communications. It alsospecifies the electrical and mechanical attributes of thebackplane, connectors and removable cards in thesesystems.

    標簽: Express PCI 電源解決方案

    上傳時間: 2013-11-17

    上傳用戶:squershop

  • DN384 精確的電源排序,防止系統損壞

      Many complex systems—such as telecom equipment,memory modules, optical systems, networking equipment,servers and base stations—use FPGAs and otherdigital ICs that require multiple voltage rails that muststart up and shut down in a specific order, otherwise theICs can be damaged. The LTC®2924 is a simple andcompact solution to power supply sequencing in a 16-pinSSOP package (see Figures 1 and 2).

    標簽: 384 DN 電源排序 防止

    上傳時間: 2013-10-29

    上傳用戶:tonyshao

  • 高功率PoE PD接口與集成反激式控制器

      To this day, Power over Ethernet (PoE) continues to gainpopularity in today’s networking world. The 12.95Wdelivered to the Powered Device (PD) input supplied bythe Power Sourcing Equipment (PSE) is a universal supply.Each PD provides its own DC/DC conversion from anominal 48V supply, thus eliminating the need for a correctvoltage wall adapter. However, higher power devicescan not take advantage of standard PoE because of itspower limitations, and must rely on a large wall adapteras their primary supply. The new LTC4268-1 breaks thispower barrier by allowing for power of up to 35W for suchpower-hungry 2-pair PoE applications. The LTC4268-1provides a complete solution by integrating a high powerPD interface control with an isolated fl yback controller.

    標簽: PoE 高功率 PD接口 集成

    上傳時間: 2014-12-24

    上傳用戶:jasson5678

  • 按鍵開關控制器簡化系統設計

      Handheld designers often grapple with ways to de-bounceand control the on/off pushbutton of portable devices.Traditional de-bounce designs use discrete logic, fl ipflops, resistors and capacitors. Other designs includean onboard microprocessor and discrete comparatorswhich continuously consume battery power. For highvoltage multicell battery applications, a high voltageLDO is needed to drive the low voltage devices. All thisextra circuitry not only increases required board spaceand design complexity, but also drains the battery whenthe handheld device is turned off. Linear Technology addressesthis pushbutton interface challenge with a pairof tiny pushbutton controllers.

    標簽: 按鍵開關 控制器 系統設計

    上傳時間: 2013-11-18

    上傳用戶:ZJX5201314

主站蜘蛛池模板: 中卫市| 新和县| 佛山市| 勃利县| 济宁市| 光山县| 井研县| 亚东县| 上犹县| 竹溪县| 涟水县| 石棉县| 灯塔市| 民勤县| 喀什市| 兰考县| 清河县| 定南县| 兰溪市| 罗城| 隆子县| 射阳县| 常熟市| 民丰县| 乐业县| 阿荣旗| 乾安县| 新民市| 西林县| 临洮县| 高州市| 星子县| 灵台县| 乌拉特前旗| 沂南县| 梧州市| 洞头县| 酉阳| 长武县| 万宁市| 平凉市|