This application note provides a detailed description of themetastable behavior in PLDs from both circuit and statisticalviewpoints. Additionally, the information on the metastablecharacteristics of Cypress PLDs presented here can help youachieve any desired degree of reliability.
上传时间： 2013-10-23
上传用户：gtzj
Differential Nonlinearity: Ideally, any two adjacent digitalcodes correspond to output analog voltages that are exactlyone LSB apart. Differential non-linearity is a measure of theworst case deviation from the ideal 1 LSB step. For example,a DAC with a 1.5 LSB output change for a 1 LSB digital codechange exhibits 1⁄2 LSB differential non-linearity. Differentialnon-linearity may be expressed in fractional bits or as a percentageof full scale. A differential non-linearity greater than1 LSB will lead to a non-monotonic transfer function in aDAC.Gain Error (Full Scale Error): The difference between theoutput voltage (or current) with full scale input code and theideal voltage (or current) that should exist with a full scale inputcode.Gain Temperature Coefficient (Full Scale TemperatureCoefficient): Change in gain error divided by change in temperature.Usually expressed in parts per million per degreeCelsius (ppm/°C).Integral Nonlinearity (Linearity Error): Worst case deviationfrom the line between the endpoints (zero and full scale).Can be expressed as a percentage of full scale or in fractionof an LSB.LSB (Lease-Significant Bit): In a binary coded system thisis the bit that carries the smallest value or weight. Its value isthe full scale voltage (or current) divided by 2n, where n is theresolution of the converter.Monotonicity: A monotonic function has a slope whose signdoes not change. A monotonic DAC has an output thatchanges in the same direction (or remains constant) for eachincrease in the input code. the converse is true for decreasing codes.
标签： Converters Defini DAC
上传时间： 2013-10-30
上传用户：stvnash
Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI noise prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of thecircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.
上传时间： 2013-11-10
上传用户：1595690
The LTC®4099 high effi ciency USB power manager andLi-Ion/Polymer battery charger seamlessly managespower distribution from multiple sources in portableapplications. It is differentiated from other USB powermanagers by its bidirectional I2C port that allows the hostmicroprocessor to control and monitor all aspects of theUSB power management and battery charging processes.In addition, a programmable interrupt generation functionalerts the host microprocessor to changes in device statusand provides unprecedented control of power managementfunctions. This high degree of confi gurability allowspost-layout changes in operation, even changes in thefi eld, and it allows a single qualifi ed device to be usedin a variety of products, thus reducing design time andeasing inventory management.
上传时间： 2013-10-22
上传用户：18602424091
为了提高环境参数采集的自动化水平，提升效率，设计了无线传感器系统。本系统运用了传感器技术、通信技术和单片机技术，实现了对环境温度、湿度、光照度以及可燃性气体浓度等参数的检测。它能够实时地与上位机进行无线通信，满足对环境参数实时监测的要求。 Abstract: In order to increase the degree of automation and improve the efficiency of the environment monitoring parameters，the wireless sensor system was developed.Combining with the technique of sensor,automatic monitoring，communication and single-chip microcomputer，it realized real-time monitoring environment parameters,such as temperature，humidity，illumination，concentration of com- bustible gas and so on.At the same time it can communicate with upper personal computers，satisfy the desire of real-time monitoring.
上传时间： 2013-11-22
上传用户：longlong12345678
针对当前安检力学试验机所能完成的试验种类单一、自动化程度低等问题，提出一种以ATmega128单片机为核心控制器的安检力学试验机的设计。详细阐述了该安检力学试验机各个组成部分的设计原理和方案，并且给出了各部分的软件设计思想和操作流程。经过大量测试试验表明：设计的安检力学试验机可以完成多达十余种的力学安检试验，完全符合相关国家标准，并且具有数据采集精度高、传输速度快、操作安全简便等特点，实现了安检设备的多功能化、数字化和自动化。 Abstract: Currently， many mechanical security testing machines have only one function. The degree of automation of them is low. To solve those problems， a new kind of mechanical security testing machine， using ATmega128 micro-controller as its core controller， has been advanced. It describes the components of the machine. The principles and the scheme in the designing processes are presented in detail， and the software architecture and the operation processes of each part are given. After having done many testing， we have reached the following conclusions: the mechanical security testing machine presented can do over ten mechanical security tests complying with related national standards. It has high data acquisition accuracy and high transmission speed. The operation of the machine is simple and safe. In general， this machine is a multi-functional， highly automatic， digitalized security testing device.
上传时间： 2013-11-05
上传用户：a67818601
针对飞行模拟器座舱数据采集的复杂性，设计了一种基于以太网分布式的数据采集控制系统，该系统是RCM5700微处理器模块上的以太网应用。在系统的基础上具体讨论了PoE技术的应用，在传输数据的网线上同时提供电流，提出并实现了一种包括辅助电源在内的完整可靠的PoE供电方案。设计采用美国国家半导体的LM5073和LM5576并根据不同的负载情况，进行稳定可靠的电压转换，以满足数据采集电路的要求。实验结果表明：该设计稳定可靠，满足低于13 W的采集节点供电要求，提高了模拟器信号采集系统的通用性和标准化程度，避免了以往数据采集节点单独繁琐的电源设计。 Abstract: Aiming at the complexity of large avion simulation and controlling，the simulator cabin distribute data collecting and control system was designed. This system is the application of RCM5700 on Ethernet. Based on this system，PoE technique that makes Ethernet can also provide power were expounded with emphasis and included FAUX design the PoE resolution was realized. To achieve the requirement of this system，LM5073 and LM5576 were used to DC-DC switch. From the data of experiment，the design filled the requirement of power-need of node whose power was lower than 13W. The application of the technique can advance the degree of simulation data collections currency and standardization and avoid designing additional power system.
上传时间： 2013-11-09
上传用户：xyipie
Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI noise prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of thecircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.
上传时间： 2013-11-16
上传用户：萍水相逢
Rotates an image by the angle degrees in the % CCW direction. degrees may be any number. % The function will put degrees in the range 0 % to 360 degrees and then into a range of -45 to 45 % degrees after performing elementary 90 degree rotations.
标签： direction the Rotates degrees
上传时间： 2013-12-10
上传用户：sardinescn
手机文件浏览程序的另外一个版本！ SMan is a system utility that manages your UIQ device. It provides functionality which manufacturers did not provide or which are difficult or impossible to do manually. SMan helps keep your UIQ device running in a "healthy" state and, to a certain degree, allows you to customize the system behaviour of your device.
标签： functionality provides manages utility
上传时间： 2013-12-09
上传用户：独孤求源
