抗工艺漂移可编程带通滤波器的设计与优化

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

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37．8kHz，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．

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 opti- mization 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 trans- fer function of the filter, data capacity of the program, and the programmable current source were optimized. Simu- lation 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%.