Switched-capacitor building blocks for adaptive systems

A number of switched-capacitor (SC) building blocks useful in adaptive systems are presented. These include a phase-lock loop, a tracking filter, a second-order equalizer with programmable gain, zeros´ frequency and zeros´ Q factor, a quadrature sine-wave generator, and a synchronous demodulator. It is shown, how a number of these signal processing blocks can be combined together to produce an adaptive channel equalizer. The operation of most of the circuits presented has been verified using discrete prototypes.