Switched-capacitor filter circuit having at least one simulated inductance having controlled switches, capacitors, and an amplifier

摘要

An easily integratable switched-capacitor filter circuit which can be employed to simulate a parallel resonance circuit has an operational amplifier having an inverting input connected to a first circuit node through a first switch, a capacitor interconnected between the first circuit node and a reference potential, a third switch interconnected between the first circuit node and a second circuit node, a capacitor interconnected between the second circuit node and the reference potential, a third switch interconnected between the second circuit node and the output of the operational amplifier, a fourth switch interconnected between the output of the operational amplifier and the first circuit node, and a fifth switch interconnected between the first circuit node and a non-grounded input terminal. The switches are respectively operated by four sequential non-overlapping clock phases such that the third and fifth switches are closed during the first clock phase, the first switch is closed during the second clock phase, the fourth switch is closed during the third clock phase, and the second switch is closed during the fourth clock phase.