抗工艺漂移可编程带通滤波器的设计与优化

为了克服集成电路制造过程中工艺变化引起滤波器中心频率的漂移,设计了一个可编程校准的OTA-C带通滤波器电路.在Top-Down的设计过程中,提出了滤波器电路设计的高层次优化方法,该方法主要包括设计空间的行为描述、约束方程描述、确定优化目标及数学求解得到较优的设计.利用该方法设计了光信号处理器中带通滤波器的电路,并且主要优化了传递函数、可编程数字信号宽度及可编程电流源设计等.仿真结果表明,该滤波器的中心频率设计标准值为37.8 kHz,当工艺漂移引起中心频率±50%的变化时,可校准系数变化范围为199%~65.6%,能够满足可编程校准的要求.

Design and optimizing of a programmable OTA-C band-pass filter immune to process variation

In order to immunize against process variation, a programmable operational transconductance amplifier (OTA)-C bandpass filter was proposed that can correct central frequency deviations caused by process variations. This high-level optimization method was formulated as a top-down design. The method used four steps starting with behavioral modeling of the performance space. It then established constraint equations. Next, the objectives of optimization were raised. The final step involved calculating and achieving an optimal solution. The programmable band-pass filter circuit was designed for optical signal processing by applying this method. Subsequently, the transfer function of the filter, data capacity of the program, and the programmable current source were optimized. Simulation results for the proposed circuit showed a calibrated value for the center frequency of 37.8 kHz. When the center frequency varied 50% to 150% from its proper frequency due to process variations, the central frequency was corrected by the programming calibration coefficient, adjusting the frequency 199% to 65.6%.