Hua-Pin Chen

Tunable current-mode and voltage-mode quadrature oscillator using a DVCCTA

A novel tunable current-mode and voltage-mode quadrature oscillator design using a single differential voltage current conveyor transconductance amplifier (DVCCTA) and four all grounded passive elements is presented. The proposed circuit offers two explicit quadrature current outputs and two quadrature voltage outputs. The oscillation condition and oscillation frequency of the proposed oscillator are independently controllable. The use of only grounded passive components makes the proposed circuit ideal for integrated circuit implementation. HSPICE simulation results are given to verify the theoretical analysis.

Versatile universal voltage-mode filter employing minimum components

A novel versatile single FDCCII-based voltage-mode universal biquadratic filter with three inputs and four outputs is presented. The proposed circuit can act as a multifunction voltage-mode filter with two inputs and four outputs and can perform simultaneous realization of voltage-mode bandreject, highpass, bandpass and lowpass filter signals from the four output terminals, respectively. On the other hand, it also can act as a universal voltage-mode filter with three inputs and a single output and can realize five generic voltage-mode filter signals without requiring any inverting input voltage signals and component-matching conditions. The proposed circuit employing single FDCCII, two grounded capacitors and two resistors, which are the minimum components necessary for realizing a second-order voltage-mode universal filtering response from the same topology. Both its active and passive sensitivities are low.

Quadrature oscillators using two CFOAs and four passive components

Two new quadrature sinusoidal oscillators using current-feedback operational amplifiers (CFOAs) as an active building block are proposed. The proposed circuits use two CFOAs with the minimum number of passive elements, namely two resistors and two grounded capacitors. The use of only grounded capacitors makes the proposed circuits ideal for integrated circuit implementation. Both proposed circuits offer the advantages of orthogonal control of the oscillation condition and oscillation frequency, availability of two quadrature sinusoidal voltage outputs and low active and passive sensitivity performances. The HSPICE simulation and experimental results are provided to demonstrate the theoretical analysis.

Voltage-mode universal biquadratic filter with one input and five outputs using two DDCCTAs

This paper presents a new high input impedance voltagemode universal biquadratic filter constructing with two differential difference current conveyor transconductance amplifiers (DDCCTAs), two grounded capacitors and two resistors. The presented filter can realize all the five standard biquadratic functions simultaneously without requiring any component matching conditions. Moreover, the circuit enjoys (i) the employment of two grounded capacitors, (ii) high input impedance and (iii) orthogonal tunability of the parameters resonance angular frequency (Bo) and quality factor (Q). HSPICE simulation results confirm the theoretical analysis.

A New Resistorless and Electronic Tunable Third-Order Quadrature Oscillator with Current and Voltage Outputs

ABSTRACT This paper presents a new resistorless and electronic tunable third-order quadrature oscillator based on voltage difference transconductance amplifiers (VDTAs). The proposed configuration using two VDTAs and three grounded capacitors has three current outputs and two voltage outputs. The resistorless circuit enjoys electronically and independently control of oscillation condition and oscillation frequency. It can simultaneously provide two quadrature output voltages, two quadrature output currents, and one amplitude-controllable output current. All the current output terminals possess high-output impedance terminals. The active and passive sensitivities of the quadrature oscillator are low. The simulation and experimental results are included to validate the theoretical analysis.

CCCCTA-based resistorless voltage and current mode quadrature oscillator

Resistorless dual-mode electronically tunable quadrature oscillator using a single current controlled current conveyor transconductance amplifier (CCCCTA) and two grounded capacitors is presented. The proposed circuit can provide both voltage-mode and current-mode simultaneously. The circuit with grounded capacitors enjoys resistorless, electronically tunable, non-interactive frequency and condition control, generates two quadrature current outputs at high impedance nodes and two quadrature voltage outputs. H-Simulation program with integrated circuit emphasis (H-Spice) simulations using Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 μm complementary metal oxide semiconductor (CMOS) technology process parameters are given to validate theoretical predictions.