Design of a Low-Power Switched-Capacitor Bandpass Filter in 0.18μm CMOS Technology with Quality Factor Tunability

ABSTRACT: In this paper, the design of lowpower secondorder switched – capacitor bandpass filter is presented in 0.18μm CMOS technology. Instead of two operational amplifiers in conventional structures only one operational amplifier is used to significantly reduce power consumption and chip area. Quality factor and maximum gain can be simply tuned by employing lowthreshold NMOS transistors as the nonoverlapping clock signals with the 1.2 volt amplitude and the period of 1msec to the switches without any variations in the central frequency. With the quality factor tuning technique the central frequency is 300Hz and the quality factor for the selective values of capacitors is 0.54. The filter has the low power consumption about 0.58nW from a 1.2 supply voltage. In this design the NMOS operational amplifier which has the high gain for the purpose of decreasing gain error consumes 141μm 2 while the total chip area of the proposed circuit is 226μm 2 .