今天，电视机与视讯转换盒应用中的大多数调谐器采用的都是传统单变换MOPLL概念。这种调谐器既能处理模拟电视讯号也能处理数字电视讯号，或是同时处理这两种电视讯号(即所谓的混合调谐器)。在设计这种调谐器时需考虑的关键因素包括低成本、低功耗、小尺寸以及对外部组件的选择。本文将介绍如何用英飞凌的MOPLL调谐芯片TUA6039-2或其影像版TUA6037实现超低成本调谐器参考设计。这种单芯片ULC调谐器整合了射频和中频电路，可工作在5V或3.3V，功耗可降低34%。设计采用一块单层PCB，进一步降低了系统成本，同时能处理DVB-T/PAL/SECAM、ISDB-T/NTSC和ATSC/NTSC等混合讯号，可支持几乎全球所有地区标准。图1为采用TUA6039-2/TUA6037设计单变换调谐器架构图。该调谐器实际上不仅是一个射频调谐器，也是一个half NIM，因为它包括了中频模块。射频输入讯号透过一个简单的高通滤波器加上中频与民间频段(CB)陷波器的组合电路进行分离。该设计没有采用PIN二极管进行频段切换，而是采用一个非常简单的三工电路进行频段切换。天线阻抗透过高感抗耦合电路变换至已调谐的输入电路。然后透过英飞凌的高增益半偏置MOSFET BF5030W对预选讯号进行放大。BG5120K双MOSFET可以用于两个VHF频段。在接下来的调谐后带通滤波器电路中，则进行信道选择和邻道与影像频率等多余讯号的抑制。前级追踪陷波器和带通滤波器的容性影像频率补偿电路就是专门用来抑制影像频率。
上传时间： 2013-11-19
上传用户：ryb
Abstract: This document details the Lakewood (MAXREFDES7#) subsystem reference design, a 3.3V input, ±12V (±15V) output, isolated power supply. The Lakewood reference design includes a 3W primary-side transformer H-bridge driver for isolated supplies, and two wide input range and adjustable output low-dropout linear regulators (LDOs). Test results and hardware files are included.
标签： MAXREFDES Lakewood Isolated Output
上传时间： 2013-11-02
上传用户：fengzimili
Abstract: This document details the Riverside (MAXREFDES8#) subsystem reference design, a 3.3V input, 12V (15V) output, isolated power supply. The Riverside reference design includes a 3W primary-side transformer H-bridge driver for isolated supplies, and one wide input range and adjustable output low-dropout linear regulator (LDO). Test results and hardware files are included.
标签： Riverside MAXREFDES Isolated Output
上传时间： 2013-11-16
上传用户：会稽剑客
Abstract: This document details the Oceanside (MAXREFDES9#) subsystem reference design, a 3.3V to 15V input,±15V (±12V) output, isolated power supply. The Oceanside design includes a high-efficiency step-up controller, a36V H-bridge transformer driver for isolated supplies, a wide input range, and adjustable output low-dropout linearregulator (LDO). Test results and hardware files are included.
上传时间： 2013-10-12
上传用户：jinyao
Abstract: With its small size and large load (10W) capability, the MAX13256 H-bridge transformer driver is an attractive solution forcharging supercapacitors (supercaps). However, a large capacitance on the output of the circuit can force the driver into fault modeat startup, due to the high initial charge current. This application note presents a solution that allows users to charge a largecapacitance without going into fault.
上传时间： 2013-10-20
上传用户：2728460838
Piezoelectric motors are used in digital cameras for autofocus,zooming and optical image stabilization. Theyare relatively small, lightweight and effi cient, but theyalso require a complicated driving scheme. Traditionally,this challenge has been met with the use ofseparatecircuits, including a step-up converter and an oversizedgeneric full-bridge drive IC. The resulting high componentcount and large board space are especially problematicin the design of cameras for ever shrinking cell phones.The LT®3572 solves these problems by combining astep-up regulator and a dual full-bridge driver in a 4mm× 4mm QFN package. Figure 1 shows a typical LT3572Piezo motor drive circuit. A step-up converter is usedto generate 30V from a low voltage power source suchas a Li-Ion battery or any input power source within thepart’s wide input voltage range of 2.7V to 10V. The highoutput voltage of the step-up converter, adjustable upto 40V, is available for the drivers at the VOUT pin. Thedrivers operate in a full-bridge fashion, where the OUTAand OUTB pins are the same polarity as the PWMA andPWMB pins, respectively, and the OUTA and OUTB pinsare inverted from PWMA and PWMB, respectively. Thestep-up converter and both Piezo drivers have their ownshutdown control. Figure 2 shows a typical layout
上传时间： 2013-11-18
上传用户：hulee
cp2012 usb驱动程序（仿真器/实验仪通用驱动） CP2102 USB to UART Bridge Controller是由台湾AMCO TEC International公司出的一个接口程序，一般用在一些CDMA上网卡或者无线上网卡上。 这个驱动只是提供接口芯片的驱动，如果各位是无线上网卡还需要厂家的程序支持。
上传时间： 2013-10-17
上传用户：开怀常笑
针对科研实验中对拉压千斤顶加载过程控制的需要，采用ATmega128单片机控制步进电机进而实现对执行系统的电动泵站实行自动控制。对力和位移的数据采集与处理及用步进电机控制电动泵站手柄的技术细节作了重点描述。通过单片机的A/D变换器对AMP放大模块采集的电桥信号作量化处理，千斤顶的操控手柄位置依电动油泵阀门开启的方向和大小作若干定位，单片机根据力或位移传感器信号，实时控制步进电机驱动手柄旋转到相应操控位置。 Abstract: This article describes the use of ATmega128 AVR microcontroller series of DBS electric pumping stations and QF100/200 separate twoway hydraulic jack to automate the process of manipulating the work of the technical content. Articles on force and displacement data acquisition and processing， and stepper motor control electric pump with the handle of the key technical details were described. Through the MCU’s A / D converter module is collected on the AMP amplification quantify the signal bridge， jack handle position control valve opening according to the direction of electric pumps for a number of positioning and size of the microcontroller based on force or displacement sensor signals， real-time control stepper motor drive control handle rotate to the appropriate location.
上传时间： 2014-01-16
上传用户：hasan2015
介绍一种简单射频识别系统设计。该设计包括阅读器、应答器和线圈3部分。由单片机控制阅读器向应答器发射无线信号，并接收应答器回送的信号，再通过分析回送信号识别物品。阅读器和应答器之间以半双工通信方式通信。 Abstract: A simple design of radio frequency identification system is given in this paper.The design includes reader,responder and winding.Through MCU，signals are sent to responder from reader，then corresponding signals are sent back. According to the analysis of the signals sent back，the objects can be identified.Half-duplex communication is adopted? between? reader? and? responder.
上传时间： 2013-10-11
上传用户：plsee
基于幅移键控技术ASK（Amplitude-Shift Keying），以C8051F340单片机作为监测终端控制器，C8051F330D单片机作为探测节点控制器，采用半双工的通信方式，通过监控终端和探测节点的无线收发电路，实现数据的双向无线传输。收发电路采用直径为0.8 mm的漆包线自行绕制成圆形空心线圈天线，天线直径为（3.4±0.3）cm。试验表明，探测节点与监测终端的通信距离为24 cm，通过桥接方式，节点收发功率为102 mW时，节点间的通信距离可达20 cm。与传统无线收发模块相比，该无线收发电路在受体积、功耗、成本限制的场合有广阔的应用前景。 Abstract: Based on ASK technology and with the C8051F340 and C8051F330D MCU as the controller， using half-duplex communication mode， this paper achieves bi-directional data transfer. Transceiver circuit constituted by enameled wire which diameter is 0.8mm and wound into a diameter （3.4±0.3） cm circular hollow coil antenna. Tests show that the communication distance between detection and monitoring of the terminal is 24cm，the distance is up to 20cm between two nodes when using the manner of bridging and the node transceiver power is 102mW. Compared with the conventional wireless transceiver modules， the circuit has wide application prospect in small size， low cost and low power consumption and other characteristics.
上传时间： 2013-10-19
上传用户：xz85592677
