基于GMR传感器的4～20mA两线制收发系统集成电路设计

发布时间：2018-11-15 17:48

【摘要】：在工业控制中,对磁场、温度、压力等信号进行实时测量时,通常有两种方式:一种是通过现场总线的方式,将信号传送至远程PC机;另一种方法是将检测到的信号转换成电流信号后进行远距离传输。当信号进行长距离传输时,传输线会受到噪声的干扰,其次传输线的分布电阻会产生电压降,使得信号传输不完整。为了避免上述问题,目前工业上广泛使用的是4~20 mA电流来传输信号。巨磁电阻(GMR)传感器具有灵敏度高、线性度好、磁滞小等优异的性能,在工业控制等方面应用广范。本文主要针对GMR传感器的工业应用,设计了一个基于GMR传感器的4~20mA两线制收发系统。在检测端,对GMR传感器的输出电压信号进行电压电流转换,以进行远距离传送;在接收端,设计电流电压转换电路以使得信号基本无失真还原。本文基于CSMC1μm40V HVCMOS工艺,在Tanner软件环境下对本设计进行电路设计与仿真。其中检测端芯片,包括调理电路与V/I转换电路两部分,调理电路由仪表放大器构成,单位增益时其共模抑制比为80.645 dB;V/I转换电路的幅度失调为0.0113%,非线性度为0.0106%,摆率为38mA/μs。在接收端的I/V转换电路,其幅度失调为0.01%,非线性度为0.005%。以上电路均满足设计指标要求,整个系统基本无失真的传送了GMR传感器检测到的信号。各个模块电路以及整个系统经过仿真满足设计指标后,分别对检测端和接收端电路进行版图设计。本系统中只对V/I转换的低压核心部分进行了MPW流片,电源管理电路采用外接方式实现,样片采用COB封装并进行测试。经过测试,此块电路的上摆率为2.67 mA/μs,下摆率为0.534 mA/μs,电流增益约为103。测试结果与仿真结果有些偏差,但是满足设计要求。
[Abstract]:In industrial control, there are usually two ways to measure the magnetic field, temperature, pressure and other signals in real time. One is to transmit the signal to the remote PC machine by the way of fieldbus. Another method is to convert the detected signals into current signals and transmit them over long distances. When the signal is transmitted over a long distance, the transmission line will be disturbed by noise, and the distributed resistance of the transmission line will produce voltage drop, which makes the signal transmission incomplete. In order to avoid these problems, it is widely used in industry to transmit signals at 20 mA current. Giant Magnetoresistance (GMR) (GMR) sensor has high sensitivity, good linearity and low hysteresis, so it is widely used in industrial control. Aiming at the industrial application of GMR sensor, this paper designs a 4~20mA two-wire transceiver system based on GMR sensor. At the detection end, the output voltage signal of the GMR sensor is converted to voltage and current for long-distance transmission. At the receiving end, a current-voltage conversion circuit is designed so that the signal can be reduced without distortion. Based on the CSMC1 渭 m 40V HVCMOS process, the circuit design and simulation are carried out in the Tanner software environment. The detector chip consists of two parts: conditioning circuit and V / I conversion circuit. The conditioning circuit is composed of instrument amplifier, and the common-mode rejection ratio is 80.645 dB; when unit gain. The amplitude misalignment of the V / I converter is 0.0113, the degree of nonlinearity is 0.0106, and the pendulum rate is 38mA/ 渭 s. At the receiving end, the I / V converter has an amplitude offset of 0.01 and a nonlinearity of 0.005. All the above circuits meet the design requirements, and the whole system basically transmits the signal detected by GMR sensor without distortion. After each module circuit and the whole system are simulated to meet the design specifications, the layout of the detecting and receiving circuits is designed respectively. In this system, only the low voltage core of the V / I conversion is implemented by MPW chip, the power management circuit is implemented by external connection, and the sample is encapsulated by COB and tested. The test results show that the upswing rate is 2.67 mA/ 渭 s, the downswing rate is 0.534 mA/ 渭 s, and the current gain is about 103 mA/ 渭 s. The test results deviate from the simulation results, but meet the design requirements.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN402;TP212

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