Novel automatic tuning system using PLL with switched capacitor circuit technique

This paper has proposed on-chip integration of an automatic tuning system for continuous-time filters using a switched-capacitor circuit and down-sampling techniques. The proposed system requires no external components and it is free of DC amplifier input-offset voltage and harmonics produced by the phase comparator. Its performance has been confirmed by computer simulations. An important property of an automatic tuning system is to keep its control signal appropriate. After the control signal converges at a desired value, operation of the system can be suspended. This will avoid noise produced by clock signals and save on power consumption. Therefore it is very effective to use the proposed system together with non-volatile analog memories