“…All the reported first order OTA based APF can be discriminated on the basis of nature of input and output signals deciding the mode of operation. Various voltage mode (VM) APFs are documented in the existing literature [2][3][4][5]8,10,[12][13][14][15]17,19,20,[22][23][24][25]27,28]. Similarly, the varieties of current mode (CM) APFs [6,7,9,11,16,21,[29][30][31][32][33] are also reported.…”