【摘要】 针对工程地震数据采集系统中程控滤波器设计时所需控制引脚较多的弊端,研制出一种仅三线控制且品质因数Q为8的可调截止频率高速低通滤波器。通过设定开关电容滤波器MAX263可编程引脚固定的编码值,并利用分频器和高速模拟开关选取MAX263的时钟输入频率,以达到其截止频率可调的目的。测试结果表明,该滤波器对阻带信号幅度衰减稳定在–21 dB以下,且截止频率切换时延稳定在3μs以内,已成功运用于浅层数字地震仪。更多还原

【Abstract】 For the drawbacks of much more control pins required with the programmable filter design in seismic data acquisition system,a high-speed adjustable cut-off frequency low-pass filter with only three control pins and Q value of 8 was designed and developed.The MAX263 programmable pins were set as fixed code values,and frequency divider and high-speed analog swith were used to select the clock input frequency of MAX263 swith capacitance filter to achieve adjustable cut-off frequency.Test results show that the attenuation level of stopband signal amplitude of the filter keep less than –21 dB,and the delay of cut-off frequency switch keep less than 3 μs.It has been successfully used in the project of shallow digital seismograph.更多还原