Research and Design of Multi-channel Programmable Anti-aliasing Filter Circuit

In electric power quality monitor system, spectrum aliasing during analog signal sampling, and interference effect from external various noise signal will lead to decrease of monitor accuracy and precision. This paper design a multi-channel four-step active Butterworth low-passing filter, which can realize multi-channel cutoff frequency adjustable anti-aliasing design by data collection card sending controlling signal, and effectively improve monitor precision. This circuit has good application in electric power quality monitor and can complete 200 Hz ~ 15 kHz cut-off frequency programmable adjusting, which can realize more electric power parameter monitor field. This paper introduces design method and module circuit diagram in detail. The circuit has advantages of modularization design, strong transplantation, and has widely use value and application prospect.