MOSFET-C filter with on-chip tuning and wide programming range

摘要

This paper describes a complete system that includes a signalnprocessing circuit, i.e., a bandpass audio filter, with its surroundingnQ and fc tuning circuitry. The filter is not only tunablenagainst fabrication tolerances or aging, but also programmable by thenuser in a wide range for both parameters. To achieve this goal, a novelnphase-locked loop architecture has been designed and implemented. Fornthe amplitude detection and control of both voltage-controllednoscillator and Q-tuning circuit, a novel scheme is also proposed. Thencomplete system has been implemented on a 0.5-Μm CMOSntechnology