Active Filter Circuits and Phase-Locked Loop (PLL)

Abstract

Active filters and phase-locked loop (PLL) and its applications are discussed in this chapter. To get acquainted with the design of active filters and the applicability in instrumentation, low pass, high pass and band pass filters are explained. The frequency selection in audio or music systems is utmost important. The selection of lower and higher cut-off frequencies decides the quality of the filters. And in public address or audio or stereophonic system bass and treble decides the quality of the sound and this comes from the proper selection of low, mid and high frequencies.