Synthesis for Current-Mode Sallen-Key Filter Using VDTAs  

作　　者：LI Yongan 

机构地区：[1]School of Physics and Electronic Engineering,Xian yang Normal University,Xianyang 712000,Shaanxi,China [2]School of Information Engineering,Shaanxi Institute of International Trade&Commerce,Xi'an 712046,Shaanxi,China

出　　处：《Wuhan University Journal of Natural Sciences》2020年第5期428-434,共7页武汉大学学报（自然科学英文版）

基　　金：the Natural Science Foundation of Shaanxi Province (2017JM6087)。

摘　　要：In this work, an original Sallen-Key second-order low-pass filter is first turned into a current-mode one by means of the adjoint network theorem. Two nodal admittance matrices(NAM) of the filter are then educed. Furthermore, these two matrices are expanded through NAM expansion approach, generating one current-mode Sallen-Key filter, which uses two compact voltage differential trans-conductance amplifiers(VDTAs) and two grounded capacitors, implements not only one low-pass transfer function but two band-pass transfer functions, and provides the non-interrelated control between the natural frequency and quality factor. As an example of the synthesized filter, a second-order VDTA filter with fo=1 MHz, Q=1, HLP=-HBP1=HBP2=1 is designed. The used synthesis approach has been confirmed with the help of circuit and computer analysis.

关 键 词：current-mode circuit Sallen-Key analog filter compact voltage differential trans-conductance amplifiers(VDTA) adjoint network theorem nodal admittance matrix expansion 

分 类 号：TN722.77[电子电信—电路与系统]