Fifth order butterworth low pass square-root domain filter design

In this study, two different fifth order square-root domain low pass Butterworth filters are designed. First filter is designed directly from fifth order transfer function. Second filter is obtained by cascading one first order and two second order filters. Both filters are designed by using state space synthesis method and constituted by current mirrors, square-root circuits, current sources and capacitors. Proposed filters are simulated by PSpice using 3V supply voltage and 0.35μm CMOS technology parameters. Both filters simulation results are compared. Ill. 6, bibl. 12 (in English; abstracts in English and Lithuanian)

A Novel Second-Order All-Pass Filter Using Square-Root Domain Blocks

In this study, a new second order all-pass filter is synthesized in the square-root domain by using the state-space method. The proposed second order all-pass filter is constituted by current mirrors, current sources, current-mode square-root circuits and capacitors. The pole frequency of the filter can be tuned electronically by varying the values of the current sources of this circuit. The filter is simulated in PSpice using 0.35um CMOS technology parameters. Quality factor of the circuit is selected as 5 and supply voltage is set to 2.7V. The simulation results show that the proposed circuit has the merits of electronic tunability. We also performed noise, THD and Monte-Carlo analyses. Various simulation results are presented to show the effectiveness of the proposed circuit