Sensors for pressure, load, temperature, acceleration andmany other physical quantities often take the form of aWheatstone bridge. These sensors can be extremely linearand stable over time and temperature. However, mostthings in nature are only linear if you don’t bend them toomuch. In the case of a load cell, Hooke’s law states that thestrain in a material is proportional to the applied stress—as long as the stress is nowhere near the material’s yieldpoint (the “point of no return” where the material ispermanently deformed).
上传时间: 2013-11-13
上传用户:墙角有棵树
ANALOG INPUT BANDWIDTH is a measure of the frequencyat which the reconstructed output fundamental drops3 dB below its low frequency value for a full scale input. Thetest is performed with fIN equal to 100 kHz plus integer multiplesof fCLK. The input frequency at which the output is −3dB relative to the low frequency input signal is the full powerbandwidth.APERTURE JITTER is the variation in aperture delay fromsample to sample. Aperture jitter shows up as input noise.APERTURE DELAY See Sampling Delay.BOTTOM OFFSET is the difference between the input voltagethat just causes the output code to transition to the firstcode and the negative reference voltage. Bottom Offset isdefined as EOB = VZT–VRB, where VZT is the first code transitioninput voltage and VRB is the lower reference voltage.Note that this is different from the normal Zero Scale Error.CONVERSION LATENCY See PIPELINE DELAY.CONVERSION TIME is the time required for a completemeasurement by an analog-to-digital converter. Since theConversion Time does not include acquisition time, multiplexerset up time, or other elements of a complete conversioncycle, the conversion time may be less than theThroughput Time.DC COMMON-MODE ERROR is a specification which appliesto ADCs with differential inputs. It is the change in theoutput code that occurs when the analog voltages on the twoinputs are changed by an equal amount. It is usually expressed in LSBs.
上传时间: 2013-11-12
上传用户:pans0ul
•Founded in Jan. 08, 2001 in Shanghai, China.•Fabless IDH focused on Analog & Mixed Signal Chip design & marketing •Over 100 IC introduced.•Over 200 OEM Customer worldwide•ISO-9000 Certified•Distribution Channel in Taiwan, China & Japan To achieve 100% customer satisfactionby producing the technically advanced product with the best quality, on-time delivery and service. Leverages on proprietary process and world-class engineering team to develop innovative & high quality analog solutions that add value to electronics equipment.
标签: Circuit Analog Design Porta
上传时间: 2013-10-24
上传用户:songnanhua
基于MDK RTX 的COrtex—M3 多任务应用设计 武汉理工大学 方安平 武永谊 摘要:本文描述了如何在Cortex—M3 上使用MDK RL—RTX 的方法,并给出了一个简单的多任务应用设计。 关键词:MDK RTX,Cortex,嵌入式,ARM, STM32F103VB 1 MDK RL—RTX 和COrtex—M3 概述 MDK 开发套件源自德国Keil 公司,是ARM 公司目前最新推出的针对各种嵌入式处理器 的软件开发工具。MDKRL—IUX 是一个实时操作系统(RTOS)内核,完全集成在MDK 编译器中。广泛应用于ARM7、ARM9 和Cortex-M3 设备中。它可以灵活解决多任务调度、维护和时序安排等问题。基于RL—I 订X 的程序由标准的C 语言编写,由Real—View 编译器进行编译。操作系统依附于C 语言使声明函数更容易,不需要复杂的堆栈和变量结构配置,大大简化了复杂的软件设计,缩短了项目开发周期。
上传时间: 2014-12-23
上传用户:Yue Zhong
Abstract: Large steel buildings, automobiles, mountains, even people survive real atmospheric lightning.
上传时间: 2013-11-11
上传用户:zgu489
数字与模拟电路设计技巧IC与LSI的功能大幅提升使得高压电路与电力电路除外,几乎所有的电路都是由半导体组件所构成,虽然半导体组件高速、高频化时会有EMI的困扰,不过为了充分发挥半导体组件应有的性能,电路板设计与封装技术仍具有决定性的影响。 模拟与数字技术的融合由于IC与LSI半导体本身的高速化,同时为了使机器达到正常动作的目的,因此技术上的跨越竞争越来越激烈。虽然构成系统的电路未必有clock设计,但是毫无疑问的是系统的可靠度是建立在电子组件的选用、封装技术、电路设计与成本,以及如何防止噪讯的产生与噪讯外漏等综合考虑。机器小型化、高速化、多功能化使得低频/高频、大功率信号/小功率信号、高输出阻抗/低输出阻抗、大电流/小电流、模拟/数字电路,经常出现在同一个高封装密度电路板,设计者身处如此的环境必需面对前所未有的设计思维挑战,例如高稳定性电路与吵杂(noisy)性电路为邻时,如果未将噪讯入侵高稳定性电路的对策视为设计重点,事后反复的设计变更往往成为无解的梦魇。模拟电路与高速数字电路混合设计也是如此,假设微小模拟信号增幅后再将full scale 5V的模拟信号,利用10bit A/D转换器转换成数字信号,由于分割幅宽祇有4.9mV,因此要正确读取该电压level并非易事,结果造成10bit以上的A/D转换器面临无法顺利运作的窘境。另一典型实例是使用示波器量测某数字电路基板两点相隔10cm的ground电位,理论上ground电位应该是零,然而实际上却可观测到4.9mV数倍甚至数十倍的脉冲噪讯(pulse noise),如果该电位差是由模拟与数字混合电路的grand所造成的话,要测得4.9 mV的信号根本是不可能的事情,也就是说为了使模拟与数字混合电路顺利动作,必需在封装与电路设计有相对的对策,尤其是数字电路switching时,ground vance noise不会入侵analogue ground的防护对策,同时还需充分检讨各电路产生的电流回路(route)与电流大小,依此结果排除各种可能的干扰因素。以上介绍的实例都是设计模拟与数字混合电路时经常遇到的瓶颈,如果是设计12bit以上A/D转换器时,它的困难度会更加复杂。
上传时间: 2013-11-16
上传用户:731140412
LAYOUT REPORT .............. 1 目錄.................. 1 1. PCB LAYOUT 術語解釋(TERMS)......... 2 2. Test Point : ATE 測試點供工廠ICT 測試治具使用............ 2 3. 基準點 (光學點) -for SMD:........... 4 4. 標記 (LABEL ING)......... 5 5. VIA HOLE PAD................. 5 6. PCB Layer 排列方式...... 5 7.零件佈置注意事項 (PLACEMENT NOTES)............... 5 8. PCB LAYOUT 設計............ 6 9. Transmission Line ( 傳輸線 )..... 8 10.General Guidelines – 跨Plane.. 8 11. General Guidelines – 繞線....... 9 12. General Guidelines – Damping Resistor. 10 13. General Guidelines - RJ45 to Transformer................. 10 14. Clock Routing Guideline........... 12 15. OSC & CRYSTAL Guideline........... 12 16. CPU
上传时间: 2013-12-20
上传用户:康郎
Linear Technology’s high performance battery management ICsenable long battery life and run time, while providing precision charging control, constantstatus monitoring and stringent battery protection. Our proprietary design techniques seamlesslymanage multiple input sources while providing small solution footprints, faster charging and100% standalone operation. Battery and circuit protection features enable improved thermalperformance and high reliability operation.
上传时间: 2013-10-13
上传用户:yyq123456789
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.
上传时间: 2013-11-02
上传用户:名爵少年
Multiple-voltage electronics systems often requirecomplex supply voltage tracking or sequencing, whichif not met, can result in system faults or even permanentfailures in the fi eld. The design diffi culties in meetingthese requirements are often compounded in distributedpowerarchitectures where point-of-load (POL) DC/DCconverters or linear regulators are scattered across PCboard space, sometimes on different board planes. Theproblem is that power supply circuitry is often the lastcircuitry to be designed into the board, and it must beshoehorned into whatever little board real estate is left.Often, a simple, drop-in, fl exible solution is needed tomeet these requirements.
上传时间: 2013-10-08
上传用户:15071087253