抗电磁干扰电流镜电路设计

发布时间：2019-04-12 18:08

【摘要】：随着无线电事业以及电子技术的发展和应用,电子设备所处环境的电磁干扰越来越严重;模拟集成电路信号处理已经进入高速度、低功耗、高集成度阶段,电子设备内部器件之间相互干扰越来越严重。电流镜作为电流模式电路中的核心模块之一,通过提高镜像电流源的抗电磁干扰能力,改善了电流模式电路的电磁兼容特性。电流模式电路相对于电压模式电路具有速度高、非线性失真小、动态范围大等优势,因而电流模式电路近来得到越来越广泛的应用。电流镜是电流模式电路的基本单元电路,电流镜性能的优良与否直接关系到电流模式电路能否正常工作。电磁干扰信号施加于基本电流镜时,电磁干扰信号会被复制到输出端,使得与电流镜输出端相连的各级器件都受到电磁干扰的影响;由于MOS管具有非线性特点,使得干扰信号叠加到直流偏置输入时,电流镜的输出端产生了直流偏移,甚至使电路不能正常工作。本文分析了产生“电荷泵”效应的基本原理,总结了产生“电荷泵”效应的两个条件。通过采取减小电流镜输出端干扰信号峰-峰值和去除“电荷泵”所引起的直流偏置两个措施增强了新型电流镜的抗电磁干扰能力。设计过程是分析已有的电流镜,包括基本电流镜、栅极滤波电流镜、栅极间低通滤波电流镜、直流反馈电流镜和低通滤波电流镜,总结了需要改进和优化的问题,利用遗传演化结构设计出了抗电磁干扰能力更强的电流镜。基本方案是利用直流反馈结构、低通滤波结构、电流分流负反馈结构和半共源共栅负反馈等结构实现了电流镜结构优化的目的。T-Spice仿真结果表明,本文提出的抗电磁干扰电流镜具有更好的抗电磁干扰能力。而且稳定性也得到了很大的提高。
[Abstract]:With the development and application of radio and electronic technology, the electromagnetic interference in the environment of electronic equipment becomes more and more serious. Analog integrated circuit signal processing has entered the stage of high speed, low power consumption and high integration, and the interferences between the internal devices of electronic devices are becoming more and more serious. As one of the core modules in the current-mode circuit, the current mirror improves the electromagnetic compatibility of the current-mode circuit by improving the anti-electromagnetic interference ability of the mirror current source. Compared with the voltage-mode circuit, the current-mode circuit has the advantages of high speed, small nonlinear distortion and large dynamic range, so the current-mode circuit has been more and more widely used recently. The current mirror is the basic unit circuit of the current mode circuit. Whether the performance of the current mirror is good or not is directly related to the normal operation of the current mode circuit. When the EMI signal is applied to the basic current mirror, the EMI signal will be copied to the output, so that all kinds of devices connected to the output end of the current mirror will be affected by the EMI. Because of the non-linear characteristics of the MOS transistor, when the interference signal is superimposed on the DC bias input, the output end of the current mirror produces a DC offset, and even makes the circuit not work properly. In this paper, the basic principle of "charge pump" effect is analyzed, and two conditions for producing "charge pump" effect are summarized. The anti-electromagnetic interference ability of the new current mirror is enhanced by reducing the peak-peak value of the interference signal at the output end of the current mirror and removing the DC bias caused by the "charge pump". The design process is to analyze the existing current mirror, including basic current mirror, gate filter current mirror, low pass filter current mirror between gates, DC feedback current mirror and low pass filter current mirror. The problems that need to be improved and optimized are summarized. A current mirror with stronger resistance to electromagnetic interference is designed by using the genetic evolution structure. The basic scheme is to optimize the current mirror structure by using DC feedback structure, low pass filter structure, current shunt negative feedback structure and semi-common source common gate negative feedback structure. The simulation results of T-Spice show that the current mirror structure is optimized. The anti-EMI current mirror proposed in this paper has better anti-EMI capability. And the stability has also been greatly improved.
【学位授予单位】：河北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN702

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