Parveen Beg

First Order Current Mode Filters and Multiphase Sinusoidal Oscillators Using MOCCIIs

An insensitive current mode versatile first order filter section with single input and multiple outputs is realized. The realization uses two multi outputs current conveyors, only one grounded resistor and one grounded capacitor. The realized current mode section provides low-pass, high-pass and all-pass responses at different outputs without any component matching constraint. The all-pass section is then cascaded with the current mode non-inverting integrator to realize a current mode multiphase sinusoidal oscillator. Thus the realized current mode oscillator provides eight phase sinusoidal outputs with equal magnitudes. The current mode outputs are loaded with same valued resistive load to achieve the eight phase voltage mode sinusoidal outputs with equal magnitudes. All the realization were designed and simulated using PSPICE. The simulation results thus obtained, verify the theory.

Multi output filter and four phase sinusoidal oscillator using CMOS DX-MOCCII

A current mode versatile first-order filter section with single input and multiple outputs is realised. The realisation uses one dual-X second generation current conveyor, two grounded resistors and two grounded capacitors. The realised current mode section provides low-pass, high-pass and all-pass responses at different outputs. The all-pass section is then cascaded with a current mode non-inverting integrator to realise a current mode four-phase sinusoidal oscillator. The current mode outputs are resistively loaded to achieve the four phase voltage mode sinusoidal outputs. All the realisations were designed and then verified using PSPICE. Experimental verification of the proposed filter sections using commercially available AD844s further confirms the validity of the theory.

Digitally controlled fully differential voltage- and transadmittance-mode biquadratic filter

This study introduces a digitally controlled biquadratic filter operating in fully differential mode and realising voltage and transadmittance functions simultaneously. The proposed circuit is based on the active element namely, digitally current controlled differential voltage current conveyor and three passive components. The proposed circuit offers wide range and non-interactive digital control over filter parameters and also exhibits wide dynamic range. The fully differential nature is well justified by the high common mode rejection ratio of the proposed circuit. Non-ideal and parasitic analyses are performed and extensive simulations carried out to verify the proposed circuit.

Biphase amplifier based precision rectifiers using current conveyors

A novel and simple circuit for precision rectifier using second-generation current conveyor (CCII) is presented in this article. The circuit basically uses a CCII-based voltage mode bi-phase amplifier, which has been used as full-wave and half-wave rectifiers. To switch the bi-phase amplifier from non-inverting to inverting mode, a MOSFET and a CCII-based comparator has been used. The circuit exhibits precision rectification over a wide range of operation and can also be implemented using commercially available ICs such as the AD844. The proposed circuits have been simulated using CMOS implementation of current conveyor with effective results.

Reconfigurable continuous time current mode first order multifunctional filter using low voltage digitally controlled CMOS CCII

The digitally controlled current conveyor has been used to realize a novel digitally controlled reconfigurable continuous time current mode first order multifunctional filter. The realized filter can provide first order current mode low pass, high pass and all pass responses without any component matching constraints. The pole frequency of the continuous time filter is directly proportional to an n-bit digital control word. The realized digitally controlled continuous time filter is designed and verified using PSPICE and the results thus obtained justify the theory.

Tunable four phase voltage mode quadrature oscillator using two CMOS MOCCIIs

In this paper a Tunable four phase sinusoidal quadrature oscillator is realized using CMOS multi-output second generation current conveyors (MOCCIIs). The circuit uses only two CMOS MOCCII and provides four phase quadrature voltage outputs with equal magnitude at the oscillating frequency. The oscillator also exhibits independent frequency control. The proposed circuit is designed and verified using PSPICE simulation.

High Performance Precision Rectifier for Analog Signal Processing

This paper presents two improved precision rectifiers, each employing two active elements and two MOS transistors. The new circuits are advantageous when compared to the most recent work [5] by enjoying high input impedance and resistor-less realization, which makes them ideal for CMOS implementation. High precision and wide frequency operation of the circuits is shown along with parasitic insensitivity. The dual-X current conveyor based novel circuits have useful analog signal processing applications and are verified through extensive computer simulations. General Terms Analog Signal Processing, Current Conveyors.

DXCCII based mixed-mode three phase oscillator

A mixed-mode three phase sinusoidal oscillator (MTSO) employing Second Generation Dual-X Current Conveyor (DXCCII) as the active element is presented. A feedback scheme consisting of two lossy integrators followed by a lossless inverting integrator is employed to obtain three voltage-mode and three current-mode sinusoidal signals simultaneously. The oscillation conditions and oscillation frequencies are independently controllable. The use of grounded passive elements ensures viability for monolithic integrated circuit implementation. Results of PSPICE simulations confirm the proposed theory.

Digitally programmable analog building block and an application

This paper presents a high performance digitally programmable CMOS analog building block termed as DCCDVCC. In the proposed building block, the bias current is digitally controlled. The DCCDVCC shows good linearity between voltages and currents, high parasitic resistances and low parasitic capacitances at port-Y and port-Z. As an application of DCCDVCC, a high-gain fully differential instrumentation amplifier is also presented. The supply voltages used are 1.25V. The DCCDVCC and the instrumentation amplifier is simulated using TSMC 0.25μm technology.