Electronically Tunable Current-Mode Square-Root-Domain First Order All-Pass Filters and Their Quadrature Oscillator Applications

2017 ◽  
Vol 5 (1) ◽  
pp. 42-48
Author(s):  
Fatma Zuhal Adalar ◽  
◽  
Ali Kircay ◽  
Mehmet Serhat Keserlioglu
Keyword(s):  
Current Mode ◽  
Square Root ◽  
Quadrature Oscillator ◽  
First Order ◽  
Electronically Tunable

Improved Electronically-Tunable Current-Mode Square-Root-Domain First-Order Multifunction Filter

2021 ◽  
pp. 2150190
Author(s):  
Manoj Kumar Jain
Keyword(s):  
Transient Response ◽  
Current Mode ◽  
Square Root ◽  
Spice Simulation ◽  
First Order ◽  
Low Pass ◽  
Multifunction Filter ◽  
Simulation Results ◽  
Electronically Tunable ◽  
High Pass

Some time back, Kircay reported an electronically-tunable current-mode square-root-domain first-order filter capable of realizing low-pass (LP), high-pass (HP) and all-pass (AP) filter functions. When simulated in SPICE, Kircay’s circuit has been found to exhibit DC offsets in case of LP and AP responses and incorrect transient response in case of HP response. In this paper, an improved circuit overcoming these difficulties/deficiencies has been suggested and its workability of the improved circuit as well as its capability in meeting the intended objectives has been demonstrated by SPICE simulation results.

An Active-C Current-Mode Universal First-Order Filter and Oscillator

2019 ◽  
Vol 28 (13) ◽  
pp. 1950219 ◽  
Author(s):  
D. Agrawal ◽  
S. Maheshwari
Keyword(s):  
Transfer Functions ◽  
Current Mode ◽  
Cmos Technology ◽  
Monte Carlo Analysis ◽  
Passive Element ◽  
First Order ◽  
Order Filter ◽  
Sinusoidal Oscillator ◽  
High Output Impedance ◽  
Electronically Tunable

This paper presents an electronically tunable current-mode first-order universal filter. The proposed circuit employs only a single Extra-X Current-Controlled Conveyor (EX-CCCII) and a single grounded capacitor, which is suitable for IC implementation. The circuit can realize three current transfer functions simultaneously, namely low-pass, high-pass and all-pass. The proposed circuit exhibits low-input and high-output impedance, which is suitable for cascading. The pole frequency of the filter can be electronically tuned, by varying the bias current of EX-CCCII. The nonidealities and parasitic effects on the circuit performance are investigated in detail. Also, the Monte Carlo analysis is done to show the effect of active and passive element mismatches on the pole frequency. An eight-phase current-mode sinusoidal oscillator and current-mode second-order filter are further realized using the proposed circuit. The functionality of the proposed circuits is verified through PSPICE simulations, using 0.25-[Formula: see text]m TSMC CMOS technology parameters.

GROUNDED CAPACITOR CM-APS WITH HIGH OUTPUT IMPEDANCE

2007 ◽  
Vol 16 (04) ◽  
pp. 567-576 ◽  
Author(s):  
SUDHANSHU MAHESHWARI
Keyword(s):  
Current Mode ◽  
Bias Current ◽  
Output Impedance ◽  
Quadrature Oscillator ◽  
Pspice Simulations ◽  
First Order ◽  
External Bias ◽  
High Output Impedance ◽  
High Output

This paper presents a new first order current mode all-pass section (CM-APS) with a grounded capacitor and employing a modified current controlled conveyor. The new circuit with high output impedance is ideal for current-mode cascading and is tunable through an external bias current. The proposed circuit is unique due to its features, not exhibited by any of the available works on the topic. An application of the circuit in realizing a quadrature oscillator is also given. The theory is validated through PSPICE simulations using real device transistors.

scholarly journals All-Pass Filter Based Linear Voltage Controlled Quadrature Oscillator

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Koushick Mathur ◽  
Palaniandavar Venkateswaran ◽  
Rabindranath Nandi
Keyword(s):  
Current Feedback ◽  
Pass Filter ◽  
Quadrature Oscillator ◽  
First Order ◽  
Feedback Amplifier ◽  
Current Feedback Amplifier ◽  
Control Node ◽  
Node Voltage ◽  
Electronically Tunable ◽  
Linear Voltage

A linear voltage controlled quadrature oscillator implemented from a first-order electronically tunable all-pass filter (ETAF) is presented. The active element is commercially available current feedback amplifier (AD844) in conjunction with the relatively new Multiplication Mode Current Conveyor (MMCC) device. Electronic tunability is obtained by the control node voltage (V) of the MMCC. Effects of the device nonidealities, namely, the parasitic capacitors and the roll-off poles of the port-transfer ratios of the device, are shown to be negligible, even though the usable high-frequency ranges are constrained by these imperfections. Subsequently the filter is looped with an electronically tunable integrator (ETI) to implement the quadrature oscillator (QO). Experimental responses on the voltage tunable phase of the filter and the linear-tuning law of the quadrature oscillator up to 9.9 MHz at low THD are verified by simulation and hardware tests.

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