DV-EXCCCII Based Resistor-Less Current-Mode Universal Biquadratic Filter

Abstract

This study aims to present a new resistor-less current-mode multi-input single-output universal filter. The current-mode’s design approach is used to obtain the proposed circuit. This circuit employs a single differential voltage extra-X current controlled current conveyor (DV-EXCCCII) and two grounded capacitors. This multifunction filter circuit offers low-pass, high-pass, all-pass, band-pass, and band-reject filters at a single output terminal without passive component matching constraints. The same circuit topology can obtain all second-order filter functions with different input conditions. The proposed circuit design is electronically adjustable with the bias current of DV-EXCCCII. Because of its high output impedance, this arrangement is suitable for cascading other current-mode circuits. The proposed circuit is simulated by Cadence Spectre with 0.18 µm UMC CMOS technology process parameters at ± 0.9 V supply voltages. The simulation results agree well with the theoretical concept of the proposed circuit.

Current-Mode Active Filter Using EX-CCCII

“…The proposed current-mode filter was compared with previous works, as shown in Table 4. The current-mode filters that use similar active devices, such as VD-EXCCCII [18], EX-CCCII in [31,32], and DV-EXCCCII in [33,34], were used for comparison. Compared with [31][32][33][34], the proposed current-mode filter can realize LPF, HPF, BPF, BSF, and APF without inverted and double input signal conditions.…”

“…The current-mode filters that use similar active devices, such as VD-EXCCCII [18], EX-CCCII in [31,32], and DV-EXCCCII in [33,34], were used for comparison. Compared with [31][32][33][34], the proposed current-mode filter can realize LPF, HPF, BPF, BSF, and APF without inverted and double input signal conditions. Compared with [18], the proposed current-mode filter uses an EX-CCCII of a lower complexity than the VD-EXCCII.…”

“…Second, the filters use passive component matching conditions [34]. The use of a single EX-CCCII based filter, made possible through the use of the current-mode technique, is advantageous in these universal filters [31][32][33][34]. Note that the realization of signal addition and subtraction in current-mode circuits is easier than for their voltage-mode counterparts.…”

“…This is advantageous for applications such active filters and oscillators. The EX-CCCII can be used for applications such as oscillators [19][20][21][22][23], instrumentation amplifiers [24,25], immittance simulators [26], precision rectifiers [27], first-order filters [28][29][30], and universal filters [31][32][33][34]. This work focuses on the EX-CCCII based universal filter.…”

“…Considering the universal filters in [31][32][33][34], these filters suffer from some drawbacks. First, in order to obtain the five filtering functions (i.e., the low-pass filter (LPF), high-pass filter (HPF), band-pass filter (BPF), band-stop filter (BSF), and all-pass filter (APF)), the filters use inverted input signals and require input matching condition [31][32][33][34]. Second, the filters use passive component matching conditions [34].…”