AT88RF020型射频识别卡及其应用

AT88RF020是13.56MHz的低端射频识别卡,遵循ISO/IEC 14443 Type B协议.着重介绍AT88RF020型射频卡的特点、工作原理及其在学校就餐管理中的应用,同时给出部分程序代码.     

Thickness Dependence of Resistivity and Optical Reflectance of ITO Films

Indium-tin-oxide （ITO） films deposited on crystalline silicon wafer and Corning glass are prepared by directcurrent magnetron sputtering method at room temperature with various thicknesses. The thickness dependences of structure, resistance and optical refectance of ITO films are characterized. The results show that when the film thickness is less than 40 nm, the resistivity and optical reflectance of the ITO film changes remarkably with thickness. The optoelectrical properties trend to stabilize when the thickness is over 55 nm. The GXRD result implies that the ITO film begins to crystallize if only the thickness is large enough.     

限流电阻柜对移圈调压器空载合闸保护作用的研究

针对某高压系统移圈调压器故障原因进行了探讨,从理论上研究了励磁涌流对调压器的破坏机理;研究了采取在调压器前端串入限流启动电阻的方法来减小励磁涌流对调压器破坏性作用的可行性。经过实测数据对比表明,加装限流电阻后,励磁涌流的幅值和持续时间下降都非常明显,操作过电压也得到抑制,具有较强的实用性。     

基于MAX1148的多通道数据采集系统的串行接口设计

高精度的多通道A/D转换器MAX1148具有功耗低、精度高、A/D转换速度快等优点。文中介绍了基于该芯片的多通道数据采集系统的应用接口,分析了该芯片的多通道数据采集系统的结构特点及工作原理,最后给出了利用MAX1148设计的典型应用电路及部分程序代码。     

ZLG7290在智能仪表面板接口设计中的应用

介绍了ZLG7290 I2C接口键盘及LED驱动器的特性及工作原理.该器件具有I2C串行接口,可驱动8位共阴级数码管或64只独立LED和64个按键.给出了ZLG7290与单片机P89LPC932的接口技术,及ZLG7290在智能仪表面板接口设计中的应用实例.     

AVR单片机与串行时钟器件DS3231的接口设计

介绍了美国Dallas公司推出的低功耗时钟器件DS3231的结构和工作原理,DS3231能对年、月、日、时、分、秒计时,且具有温度补偿、闰年补偿等多种功能.给出了AVR单片机ATmega8与DS3231的软、硬件接口设计.     

Substrate Dependence of Properties of Sputtered ITO Films

High-quality indium-tin-oxide (ITO) films are deposited on p-type Czochralski silicon and 7059 Coming glass by direct-current magnetron sputtering at various temperatures. The structural, electrical and optical properties of the ITO films are investigated as functions of the substrate temperature. A comparison between the characteristics of the ITO films on silicon and Coming glass is presented. The results show that for the ITO film on silicon,the nucleation begins from room temperature; the resistivity reaches a maximum value at 75℃; the reflectivity increases with increasing temperature; when temperature is above 125℃, the ITO grows in a three-dimensional manner and forms a granular structure. However, for the ITO film on glass, it is still in an amorphous state at 75℃. Moreover, both the resistivity and the reflectivity decrease with increasing temperature. Above 125℃, the ITO grows in a two-dimensional manner and forms a domain structure.     

LED显示驱动芯片BN5279(A)及其串行接口应用

BN5279(A)是贝能科技有限公司生产的集成LED显示驱动器，具有工作电压低、串行接口、带有64键的键盘矩阵控制等特点。文中介绍了该电路的主要特性及工作原理，给出了BN5279(A)与AT89C2052微处理器的连接电路及程序代码。     

基于PIC16单片机和HM1500的湿度测量

HM1500湿度变送器是一种精密湿度传感器,采用HUMIREL公司的湿敏电容HS1101设计制造,可用于加热、通风和空气调节(HAVC)系统、环境监控、洁净空间、蔬菜大棚、粮食仓贮等的湿度检测与控制.介绍了HM1500湿度变送器的主要性能指标,给出了其与PIC系列单片机的接口及温度误差的补偿方法.     

集成温度传感器AD592及其应用

集成温度传感器AD592具有价格低、精度高、线性好、防水、防腐蚀等优点.文中介绍了该电路的工作特性及工作原理,给出了利用AD592设计的典型应用电路.利用AD592设计的电路可以将温度或温差转换为对应的电压,还可以将温度转换为4 mA～20 mA的电流或相应的数字信号,从而与DDZ-Ⅲ仪表或单片机相连组成温度测控系统.