Electronically tunable versatile voltage-mode universal filter

Electronically tunable multiple-input single-output voltage-mode multifunction filter employing simple CMOS OTAs

“…Considering the number of OTA-based universal biquad filter, the voltage-mode multiple inputs and single output filtering circuits have been proposed [5]- [15] which enjoy a variety of circuit characteristics with different input voltages, and low sensitivities. However, the reported filters suffer from one or more of the following disadvantages:…”

“…(3) The use of two kinds of active components [6], [7], [11], [13], [14], [15]. (4) The use of floating capacitors [6], [9], [10], [12], [15].…”

New Electronically Tunable Voltage-Mode Lowpass, Highpass, Bandpass Filter Using Simple OTAs

“…On the other hand, the filters using grounded capacitors are beneficial from the point of view of IC implementation [3]. In the literature, several voltage-mode biquad filters using OTAs have been proposed [4]- [23]. Considering the number of input and output ports, these filters can be divided into four categories: (i) a single-input, single-output (SISO) type [4]- [6], (ii) a single-input, multiple-output (SIMO) type [1], [7]- [12], (iii) a multiple-input, single-output (MISO) type [13]- [16], and (vi) a multiple-input, multiple-output (MIMO) type [17]- [23].…”

“…In the literature, several voltage-mode biquad filters using OTAs have been proposed [4]- [23]. Considering the number of input and output ports, these filters can be divided into four categories: (i) a single-input, single-output (SISO) type [4]- [6], (ii) a single-input, multiple-output (SIMO) type [1], [7]- [12], (iii) a multiple-input, single-output (MISO) type [13]- [16], and (vi) a multiple-input, multiple-output (MIMO) type [17]- [23]. Generally, the SISO filters can realize multi-function outputs by altering the connection way of the circuits [4]- [6], but altering the connection way can only realize a filtering output at a time.…”

“…Generally, the SISO filters can realize multi-function outputs by altering the connection way of the circuits [4]- [6], but altering the connection way can only realize a filtering output at a time. The MISO and MIMO filters can realize multifunction outputs simultaneously [13]- [23] need input signal matching. The SIMO filters can simultaneously realize standard filters, namely lowpass (LP), bandpass (BP) and highpass (HP) filters at a time without altering the connection way of the circuits and without input signal matching.…”