Mixed-Mode Universal Biquad Filter Using OTAs

2019 ◽  
Vol 29 (10) ◽  
pp. 2050162 ◽  
Author(s):  
Data R. Bhaskar ◽  
Ajishek Raj ◽  
Pragati Kumar

This paper introduces an electronically tunable mixed-mode universal biquad filter configuration employing four single output operational transconductance amplifiers (OTAs), one dual output OTA and two grounded capacitors (GCs) (ideal for integrated circuit implementation and absorbing shunt parasitic capacitances). The presented structure can realize all second-order filter functions, namely, low pass (LP), high pass (HP), band pass (BP), band reject (BR) and all pass (AP) responses in voltage mode (VM), current mode (CM), transresistance mode (TRM) and transconductance mode (TCM) using appropriate selection(s) of input signals. The cut-off frequency ([Formula: see text] and bandwidth (BW) of the realized filters can be tuned orthogonally through the transconductance (by varying the bias currents) of the OTAs. The proposed biquad configuration enjoys low active and passive sensitivities. The workability of this multifunctional biquad filter topology has been confirmed through simulations using MATLAB and Analog Design Environment (ADE) spectre tool provided by Cadence Virtuoso, using 0.18[Formula: see text][Formula: see text]m CMOS process parameter. The post-layout simulations have also been carried out to validate the theory.

2016 ◽  
Vol 25 (09) ◽  
pp. 1650107 ◽  
Author(s):  
Ali Kircay ◽  
Selim Borekci

In this paper, electronically-tunable, current-mode biquad is proposed by using multiple-output operational transconductance amplifiers (MO-OTAs). The proposed circuit has one input and two outputs. Without changing the circuit topology, low-pass (LP), and band-pass (BP) responses can be realized. The filter is realized by using two MO-OTAs, a single-output OTA (SO-OTA), a two-output OTA and two grounded capacitors. The biquad is designed based on first-order LP filter or lossy integrator blocks. The feedback block is applied to the filter circuit in order to obtain high quality factor values greater than 1/2. The center frequency and the quality factor of the LP and BP filters can be electronically tuned by DC current of OTAs. The total power dissipation of the proposed biquad is approximately 10[Formula: see text]mW at [Formula: see text][Formula: see text]V supplied voltage. The theoretical analysis is also confirmed with SPICE simulations.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Rajeshwari Pandey ◽  
Neeta Pandey ◽  
Navin Singhal

This paper presents a dual mode, single input multioutput (SIMO) biquad filter configuration using single voltage differencing transconductance amplifier (VDTA), three capacitors, and a grounded resistor. The proposed topology can be used to synthesize low pass (LP), high pass (HP), and band pass (BP) filter functions. It can be configured as voltage mode (VM) or current mode (CM) structure with appropriate input excitation choice. The angular frequency (ω0) of the proposed structure can be controlled independently of quality factor (Q0). Workability of the proposed biquad configuration is demonstrated through PSPICE simulations using 0.18 μm TSMC CMOS process parameters.


2009 ◽  
Vol 18 (04) ◽  
pp. 665-680 ◽  
Author(s):  
SHAHRAM MINAEI

In this paper, an electronically tunable current-mode (CM) universal biquad filter is proposed. The proposed filter employs three dual-X second-generation current conveyors (DXCCIIs), two grounded capacitors and four NMOS transistors acting as resistors. The proposed filter simultaneously realizes standard filter functions such as low-pass (LP), band-pass (BP), and high-pass (HP) responses. The notch (NH) and all-pass (AP) functions can also be obtained by connecting appropriate output currents directly without using additional active elements. The output signals are obtained at high output impedance terminals, which is important for easy cascading in CM operation. SPICE simulation results are given to verify the theoretical analyses.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Dinesh Prasad ◽  
Mayank Srivastava ◽  
D. R. Bhaskar

A new resistorless single-input-multi-output (SIMO) universal transadmittance (TA) type filter employing two voltage differencing transconductance amplifiers (VDTA) and two grounded capacitors is proposed. The proposed topology realizes simultaneously low pass (LP), high pass (HP), and band pass (BP) filter functions. Band rejects (BR) and all pass (AP) filters are also realizable through appropriate connections of currents. The proposed configuration also offers independent control of natural angular frequency (ω0) and bandwidth (BW) and low active and passive sensitivities. The workability of proposed configuration has been demonstrated through PSPICE simulations with TSMC CMOS 0.18 μm process parameters.


2013 ◽  
Vol 22 (01) ◽  
pp. 1250064 ◽  
Author(s):  
NEETA PANDEY ◽  
SAJAL K. PAUL

The configuration with electronic tunable characteristics that can work in mixed mode may be useful from IC realization viewpoint and application adaptability. This paper proposes an electronically tunable mixed mode universal filter based on multiple output current controlled current conveyor (MOCCCII) and this single topology without any alteration can be used in all four modes i.e., voltage (VM), current (CM), transimpedance (TIM) and transadmittance (TAM). The architecture uses four MOCCCIIs and two grounded capacitors; and can realize universal filter functions — low pass (LP), band pass (BP), high pass (HP), notch (NF) and all pass (AP) for all four modes. Moreover the input impedance is high and output impedance is low for voltage signal and vice-versa for current signal, hence the proposed topology is suitable for cascading for all four modes. The workability of the proposed circuit has been verified via SPICE simulations using AMS 0.35 μm CMOS technology.


2017 ◽  
Vol 26 (07) ◽  
pp. 1750121 ◽  
Author(s):  
Thanat Nonthaputha ◽  
Montree Kumngern

This paper presents new programmable universal biquadratic filters using current conveyor transconductance amplifiers (CCTAs) by which both voltage- and current-mode filters can be obtained. The proposed filters use second-generation current conveyor (CCII) which is the first stage of CCTA to operate as current conveyor analog switch (CCAS) and this CCAS will be used to program the filtering functions such as low-pass, high-pass, band-pass, band-stop and all-pass filters. Unlike previous universal filters, the filtering functions of the proposed filters can be programmed using the bias currents of CCTAs without changing any input and output connections. The natural frequency and quality factor of all filtering functions can be controlled electronically and orthogonally using the bias currents of transconductance amplifiers. Also gain response of all transfer functions can be adjusted. The active and passive sensitivities of the filters are low. The proposed programmable filters have been simulated using 0.18[Formula: see text][Formula: see text]m CMOS process from TSMC. PSPICE simulation results are included to confirm workability of the proposed circuits.


2010 ◽  
Vol 19 (08) ◽  
pp. 1641-1650 ◽  
Author(s):  
FIRAT KAÇAR

A new tunable CMOS FDNR circuit is proposed. The circuit is based on the transcapacitive gyrator approach with both transcapacitive stages realized by MOS transistors configuration. This FDNR element lends itself well to the design of low-pass ladder filters and its use will result in a more efficient integrated circuit implementation than filters that simulate floating inductors utilizing resistive gyrators. The applications of FDNR to realize a current-mode fifth-order elliptic filter and current mode sixth-order elliptic band-pass filter are given. The proposed FDNR is simulated using CMOS TSMC 0.35 μm technology. Simulation results are given to confirm the theoretical analysis.


2013 ◽  
Vol 787 ◽  
pp. 501-507
Author(s):  
Saksit Summart ◽  
Chanchai Thongsopa

This article presents current-mode universal biquad filters based on CDTAs. The filter circuits using four CDTAs and two grounded capacitors which are able to provide low-pass, high-pass, band-pass, band-reject and all-pass functions. The pole frequency can be orthogonally controlled from quality factor and the circuits have high output impedance appropriate for cascade connection application in current mode which is capable to directly drive load. This qualification is very appropriate for further development into an integrated circuit. The results of PSPICE simulation program are corresponding to the theoretical analysis.


2012 ◽  
Vol 21 (01) ◽  
pp. 1250013 ◽  
Author(s):  
MEHMET SAGBAS ◽  
MUHAMMET KOKSAL

In this paper, a general electronically tunable resistorless biquad, which realizes current ratio transfer function using current backward transconductance amplifiers is proposed. The biquad contains only two active components and two grounded capacitors, which make it convenient for production by the integrated circuit technology. The proposed biquad realizes all of the basic second order filter characteristics: low pass, high pass, band pass, band reject, and finally all pass. It is convenient for cascading with other similar biquads as well as with any two-port circuit with low impedance input to achieve higher order filter characteristics. The simulations that are performed using PSPICE simulator exhibit satisfactory results coherent with the theory.


2016 ◽  
Vol 25 (05) ◽  
pp. 1650035 ◽  
Author(s):  
Meili Cao ◽  
Haizhen He ◽  
Hairong Lin ◽  
Hao Peng ◽  
Bohui Zhu

In this paper, a new active current-mode (CM) minimal component, cascaded current differencing unit (CCDU) and a CM nth-order filter based on the CCDU have been presented. The proposed CCDU simplifies the design of the CM nth-order filter circuit considerably. The proposed nth-order circuit, which adopts only an active component and n grounded capacitors, can simultaneously realize low-pass (LP), band-pass (BP) and high-pass (HP) filter responses. It enjoys the simple configuration and is suitable for integrated circuit (IC) fabrication. PSPICE simulations and experimental tests for CM third-order filter based on this structure have also been conducted and the results have good agreement with the theoretical analysis.


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