无极性RS485接口集成电路的设计  

Design of Non-polarity RS485 Interface IC

作　　者：段小军 罗小巧[1] DUAN Xiaojun;LUO Xiaoqiao(School of Physical Science and Technology,Central China Normal Nniversity,Hubei 430079,China.)

机构地区：[1]华中师范大学物理科学与技术学院

出　　处：《集成电路应用》2019年第11期19-21,共3页Application of IC

基　　金：湖北省教育系统科技创新课题项目

摘　　要：在RS485总线通信中,有极性RS485芯片采用的平衡输入是存在极性的。具体连接时,需要严格匹配数据总线上的极性。而在实际中,传输距离远、从节点数量多等问题很容易将平衡输入端口极性和总线上的极性接反,这也是造成RS485总线数据传输失败主要原因。而在完成无极性信号的传输上,之前大多选择在A、B端增加外部的接口电路,将A、B端输出信号调制为无极性信号,然后传输到总线上。设计将电路结构集成到RS485芯片内部,从而实现A、B信号无极性,并简化电路结构。In the communication of RS485 bus, the balance input adopted by the chip RS485 with polarity has polarity, and the specific connection needs to strictly match the polarity on the data bus. In practice, problems such as long transmission distance and large number of slave nodes can easily reverse the polarity of the balanced input port and the polarity on the bus, which is also the main reason for the failure of data transmission on RS485 bus. In order to complete the transmission of non-polar signals, most of the previous choices were to add external interface circuits at A and B terminals, modulating the output signals at A and B terminals into non-polar signals, and then transmitting them to the bus. In this paper, the main design is to integrate this part of circuit structure into the internal of RS485 chip, so as to realize the non-polarity of A and B signals and simplify the circuit structure. In practical application.

关 键 词：集成电路设计 RS485 无极性 自适应接口 

分 类 号：TN402[电子电信—微电子学与固体电子学] TP336[自动化与计算机技术—计算机系统结构]