Considerations for high-frequency switched-capacitor ladder filters

Monolithic filters using switched-capacitor techniques are beginning to be used in commercial audio frequency communication circuits [1], [2], [10]. The fact that these filters are MOS compatible, high precision and low power makes them very attractive in these filter applications. The usefulness of switched-capacitor filters will be greatly increased if the frequency range of these filters can be extended above the voice band. The purpose of this paper is to present the theoretical considerations as well as practical circuits which are useful to the designer attempting to implement high-speed filters.