What would happen if someone connected 24V to your12V circuits? If the power and ground lines were inadvertentlyreversed, would the circuits survive? Does yourapplication reside in a harsh environment, where the inputsupply can ring very high or even below ground? Evenif these events are unlikely, it only takes one to destroya circuit board.
上传时间: 2013-10-26
上传用户:jackandlee
Specifying the right reference and applying it correctly isa more difficult task than one might first surmise, consideringthat references are only 2- or 3-terminal devices.Although the word “accuracy” is most often spoken inreference to references, it is dangerous to use this wordtoo freely because it can mean different things to differentpeople. Even more perplexing is the fact that a referenceclassified as a dog in one application is a panacea inanother. This application note will familiarize the readerwith the various aspects of reference “accuracy” andpresent some tips on extracting maximum performancefrom any reference.
标签: 电压基准
上传时间: 2013-10-15
上传用户:liuwei6419
For a variety of reasons, it is desirable to charge batteriesas rapidly as possible. At the same time, overchargingmust be limited to prolong battery life. Such limitation ofovercharging depends on factors such as the choice ofcharge termination technique and the use of multi-rate/multi-stage charging schemes. The majority of batterycharger ICs available today lock the user into one fixedcharging regimen, with at best a limited number ofcustomization options to suit a variety of application needsor battery types. The LTC®1325 addresses these shortcomingsby providing the user with all the functionalblocks needed to implement a simple but highly flexiblebattery charger (see Figure 1) which not only addressesthe issue of charging batteries but also those of batteryconditioning and capacity monitoring.
上传时间: 2013-10-19
上传用户:royzhangsz
Portable, battery-powered operation of electronic apparatushas become increasingly desirable. Medical, remotedata acquisition, power monitoring and other applicationsare good candidates for batteryoperation. In some circumstances,due to space, power or reliability considerations,it is preferable to operate the circuitry from a single 1.5Vcell. Unfortunately, a 1.5V supply eliminates almost alllinear ICs as design candidates. In fact, the LM10 opamp-reference and the LT®1017/LT1018 comparators arethe only IC gain blocks fully specifi ed for 1.5V operation.Further complications are presented by the 600mV dropof silicon transistors and diodes. This limitation consumesa substantial portion of available supply range, makingcircuit design diffi cult. Additionally, any circuit designedfor 1.5V operation mustfunction at end-of-life batteryvoltage, typically 1.3V. (See Box Section, “Componentsfor 1.5V Operation.”)
标签: Circuitry Operation Single Cell
上传时间: 2013-10-30
上传用户:hz07104032
为解决直流逆变交流的问题,有效地利用能源,让电源输出最大功率,设计了高性能的基于IR2101最大功率跟踪逆变器,并以SPMC75F2413A单片机作为主控制器。高电压、高速功率的MOSFET或IGBT驱动器IR2101采用高度集成的电平转换技术,同时上管采用外部自举电容上电,能够稳定高效地驱动MOS管。该逆变器可以实现DC/AC的转换,最大功率点的跟踪等功能。实际测试结果表明,该逆变器系统具有跟踪能力强,稳定性高,反应灵敏等特点,该逆变器不仅可应用于普通的电源逆变系统,而且可应用于光伏并网发电的逆变系统,具有广泛的市场前景。 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
上传时间: 2013-11-17
上传用户:lliuhhui
在理论分析循环码编码和译码基本原理的基础上,提出了基于单片机系统的(24,16)循环码软件实现编码、译码的方案。仿真结果表明(24,16)循环码能有效地克服来自通讯信道的干扰,保证数据通信的可靠及系统的稳定,使误码率大幅度降低。本论文对(24,16)循环码的研究结果表明,可以有效地降低错误概率和提高系统的吞吐量,实现纠错仅需要在接收端增加有限的存储空间和计算复杂度,具有一定的实用价值。 Abstract: Based on analyzing the theory of encoding and decoding of cyclic code, this paper showed the schemes of encoding and decoding of(24,16)cyclic code by the software and based on microcontroller. Simulation results show that using (24,16) cyclic codes can effectively overcome the interference from communication channel, ensure the reliability and stability of data communication systems, and reduce the bit error rate greatly. The results of this paper show that by using the (24,16) cyclic code, the error rate can be reduced and the system throughput can be improved. Meanwhile, the system only needs to enlarge limited storage space and computation the complexity at the receiving end to realize error correction. Thus the (24,16) cyclic code has a practical value.
上传时间: 2013-11-09
上传用户:gaoliangncepu
利用单片机具有的智能程序控制的特点,设计了基于STC89C52单片机的"二极管特性测试器",可对二极管一般特性进行快速测试。通过稳定线性电流源给二极管加载恒定电流,然后由高精度模数转换器测试其压降,以此为基础可判断二极管好坏、检测二极管极性和测试二极管伏安特性等,避免了用万用表测试只能测得极性而不知其特性这一缺点。可用于电子设计制作过程中对二极管进行快速测试,以确定被测二极管是否满足电路的设计要求。 Abstract: By making good use of the intelligent control function of the Micro Controller Unit (MCU), the diode trait tester was designed based on the STC89C52,which could be used to test the trait of a diode rapidly. By loading constant current to diode through the stable linear current source, and measuring the voltage drop of the diode by high-precision analogue-to-digital converter (ADC), it can judge whether the diode is good or not, distinguish the polarity of the diode, and test the trait that the diode, which can avoid the fault of using a multimeter can only measure the polarity but not the trait. This device can be used to test the trait of a diode quickly,and to make sure that whether a diode can be used in the electronic design or not.
上传时间: 2013-11-13
上传用户:assef
Designing read/write device (RWD) units for industrial RF-Identification applications is strongly facilitated by the NXP Semiconductors HITAG Reader Chip HTRC110. All needed function blocks, like the antenna driver, modulator demodulator and antenna diagnosis unit, are integrated in the HTRC110. Therefore only a minimum number of additional passive components are required for a complete RWD. This Application Note describes how to design an industrial RF-Identification system with the HTRC110. The major focus is dimensioning of the antenna, all other external components including clock and power supply, as well as the demodulation principle and its implementatio
上传时间: 2013-10-22
上传用户:zhengjian
为解决我国水位监测野外条件下长期无人看守的问题,研制开发了基于MSP430单片机的智能水位计。从其组成到各功能分别进行了详细的介绍,该智能水位计不仅实现了水位数据的实时监测、记录和定期采集等多种工作模式,而且提高了水位监测精度,实现了水位监测的智能化。 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.
上传时间: 2013-11-17
上传用户:417313137
The MAX9257/MAX9258 programmable serializer/deserializer (SerDes) devices transfer both video data and control signals over the same twisted-pair cable. However, control data can only be transmitted during the vertical blank time, which is indicated by the control-channel-enabled output (CCEN) signal. The electronic control unit (ECU) firmware designer needs to know how quickly to respond to the CCEN signal before it times out and how to calculate this duration. This application note describes how to calculate the duration of the CCEN for the MAX9257/MAX9258 SerDes chipset. The calculation is based on STO timeout, clock frequency, and UART bit timing. The CCEN duration is programmable and can be closed if not in use.
上传时间: 2014-01-24
上传用户:xingisme