PC-configurable RLC resonator yields single-output filter

摘要

THIS DESIGN IDEA presents a versatile filter circuit for low-power-consumption instrumentation that you can program from your PC using the parallel port. The circuit uses analog switches and latches instead of digital potentiometers for the digital control (figures 1 and 2). By running simple software code on the PC, you can configure a single robust design to work as a lowpass, highpass, or band pass filter, and you can also select the desired center frequency, ω{sub}0(Listing 1) Unlike a similarly controllable design (Reference 1) this design is a single-out-put-at-a-time filter. Many power-sensitive systems do not require simultaneous-filter functions.