十四阶开关电容带通滤波器的研究与设计

发布时间：2018-02-23 22:13

本文关键词： 开关电容带通滤波滤波器双四结构　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：本课题对带通开关电容滤波器工作原理进行介绍,深入分析了影响开关电容滤波器性能的非理想因素,然后设计了由八阶切比雪夫高通滤波器和六阶椭圆低通滤波器组成的带通滤波器。在Matlab中对滤波器进行系统级设计,确定滤波器的结构、传递函数以及各级系数。基于滤波器系统,为了有效的减小滤波器的共模噪声并提高输出摆幅,滤波器在晶体管级设计时采用全差分电路,采用csmc0.5um工艺在Cadence环境下对电路进行了晶体管级仿真,完成滤波器的版图设计后对版图进行了后仿真。最后对滤波器的芯片进行了测试,并分析测试结果。在对滤波器中非理想因素分析过程中,采样开关的导通电阻会存在热噪声,会增加滤波器通带内的噪声,其次滤波器系统中电容的不匹配会造成传递函数的发生偏差,进而影响滤波器性能如通带纹波,阻带衰减速率等性能,最后由于此电路中最基本的结构为开关电容积分器,积分器中的运放有限增益、带宽和转换速率会影响积分器的精度影响系统性能。在系统级设计过程中,为了保证较快的阻带衰减速度,此带通滤波器采用八阶切比雪夫高通滤波器和六阶椭圆低通滤波器的组合,完成滤波器传递函数的设计后确定各级的系数,然后采用csmc 0.5um工艺,对整体电路在Cadence下仿真,得到晶体管级仿真结果:通带增益约为93dB,阻带衰减速度大于78dB/2倍频。本课题还完成了的滤波器版图,并进行了后仿真,后仿真结果得到通带的增益约为84.2dB。对芯片进行测试,测试结果显示滤波器在通带频率低于130kHz时通带范围受到低通和高通滤波器时钟的控制,通带增益为85.6dB,通带纹波为0.5dB,通带噪声为1.3mVrms/Hz1/2,阻带衰减速度均约为74dB/2倍频。
[Abstract]:In this paper, the working principle of bandpass switched capacitor filter is introduced, and the non-ideal factors that affect the performance of switched capacitor filter are deeply analyzed. Then, a bandpass filter consisting of eighth order Chebyshev high-pass filter and sixth-order elliptical low-pass filter is designed. The filter is system-level designed in Matlab, and the structure of the filter is determined. Based on the filter system, in order to effectively reduce the common mode noise of the filter and increase the output swing, the filter is designed with a fully differential circuit at the transistor level. The transistor-level simulation of the circuit is carried out under the environment of Cadence using csmc0.5um process. The layout of the filter is designed and the layout is simulated. Finally, the chip of the filter is tested. During the analysis of the nonideal factors of the filter, the on-resistance of the sampling switch will have thermal noise, which will increase the noise in the filter passband. Secondly, the mismatch of the capacitance in the filter system will cause the deviation of the transfer function, which will affect the performance of the filter, such as pass band ripple, stopband attenuation rate and so on. Finally, because the most basic structure of this circuit is the switched capacitor integrator, The limited gain, bandwidth and conversion rate of the integrator will affect the performance of the integrator. In the process of system level design, in order to ensure the fast stopband attenuation speed, The band pass filter adopts the combination of the eighth order Chebyshev high pass filter and the sixth order elliptical lowpass filter. After the design of the filter transfer function, the coefficients of all levels are determined, and then the whole circuit is simulated under Cadence using csmc 0.5um technology. The results of transistor-level simulation are as follows: pass band gain is about 93 dB, and stopband attenuation speed is more than 78 dB / 2. The filter layout completed in this paper has been simulated, and the latter simulation results show that the pass band gain is about 84.2 dB. The chip is tested. The test results show that the passband range of the filter is controlled by low pass and high pass filter clock when the passband frequency is below 130 kHz. The passband gain is 85.6 dB, the passband ripple is 0.5 dB, the passband noise is 1.3 mVrms / Hz1 / 2, and the stopband attenuation rate is about 74 dB / 2.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713.5

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