A new MOS-C multifunction filter and its third order oscillator application

The paper presents a new current mode biquadratic filter with one input and three outputs using differential voltage current conveyor (DVCC) and four passive components. The proposed circuit can simultaneously realize low-pass, band-pass, and high-pass filter functions without changing the circuit topology and passive elements. The circuit exhibits a good frequency performance and low-sensitivity figures. PSPICE simulation using 0.5 μm CMOS parameters are given to validate the proposed circuit. The circuit provides a simple yet novel solution to the current-mode filtering after appropriate incorporation of current sensing elements in form of current buffers.

A low power current controllable single-input three-output current-mode filter using MOS transistors only

In this paper, a new circuit based on single voltage differencing trans-conductance amplifier (VDTA) is presented which realizes band pass (BP) and high pass (HP) filtering functions in trans-admittance-mode (TAM). In addition of single VDTA as active element, it also consists of two grounded capacitors and one resistor as three passive elements. Moreover, the proposed circuit can be operated at low voltage (±1V) power supply which results low power consumption. The circuit also exhibits low active and passive sensitivity. The validity of proposed filter is verified in CMOS technology through PSPICE simulation.

In this paper, four new sinusoidal waveform generators based on the operational transresistance amplifier (OTRA) are presented. The first proposed circuit is a minimum component RC sinusoidal oscillator circuit with one OTRA and a few passive components. The second and third proposed circuits consist of one OTRA and a few passive components, among them two passive components are connected to ground. These circuits are able to control the condition of oscillation and frequency of oscillation independently. The fourth proposed quadrature oscillator circuit uses two OTRAs as main active building blocks and a few external passive components to generate the oscillations. The commercially available IC AD844AN has been adopted to implement the proposed circuits on a laboratory breadboard with external passive components. Both the SPICE simulation and experimental results are given to verify the theoretical analysis of the proposed circuits.

Background: Three high input impedances voltage-mode first-order filters are presented. Methods: The first proposed circuit uses one multi-output second-generation current conveyor, two resistors and one grounded capacitor. The second proposed circuit uses two second-generation current conveyors, three resistors and one grounded capacitor. The third proposed circuit uses one multi-output second-generation current conveyor, one resistor and two grounded capacitors. Results: First-order lowpass and allpass filters can be simultaneously obtained in the first proposed circuit. First-order lowpass, highpass and allpass filters can be simultaneously obtained in the second proposed circuit. The third proposed circuit can realize first-order allpass filter. Conclusion: All the proposed circuits have the advantages of high input impedances and using only grounded capacitors.

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 (ω 0) 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.

This chapter primarily discusses the design of four different dual-band SPDT and T/R band-pass filter-switches (namely, Design 1, 2, 3 and 4). These switches demonstrate not only switching but also band-pass filtering functions. Design 1 presents a 0.18-µm CMOS dual-band T/R switch having a band-pass filtering function working concurrently over 35.5–43.7 GHz and 56.4–63 GHz. The developed filter-switch has multiple ports, with each port handling a dual-band signal concurrently, and a high isolation (more than 50 dB over the two pass bands) between ports, which making it attractive for the use of the dual-band RF systems. It is also useful for systems having multi-port and dual-band concurrent operation with band-pass filtering and high isolation. The filter-switch is designed based on a 3rd dual-band band-pass filter with its capacitors replaced with shunt nMOS transistors to accommodate switching function. Design 2 describes a 0.18-µm CMOS concurrent T/R switch having dual-band-pass filtering function across 17.2-27.3 GHz and 52.5-66.5 GHz. The filter-switch is implemented with dual-band quarter-wavelength LC networks and dual-band resonators with their capacitor replaced with shunt nMOS transistor. The on/off states of the filter-switch are determined through a quarter-wavelength characteristic of the dual-band LC network and the off/on states of the shunt transistor. The developed T/R filter-switch has multiple ports, with each port being capable of handling dual bands concurrently, making it attractive for the use in multi-band RF systems, and is needed for multi-port and multi-band concurrent operations with band-pass filtering function. Design 3 shows 0.18-µm CMOS dual-band SPDT and T/R switches having band-pass filtering function over 14.6-30.4 GHz, 48-62.3 GHz and 14.6-30.3 GHz, 48.4-64.8 GHz, respectively. The filter-switches are based on a 2nd order band-pass filter. The dual-band band-pass filtering SPDT can operate in single-band mode at 24 or 60 GHz as well as concurrent dual-band modes at 24 and 60 GHz. The dual-band band-pass filtering T/R switch’s operation is more versatile, and it can be used for various individual and concurrent switching functions. It can operate in single-band transmitting or receiving mode at 24 and 60 GHz, and concurrent dual-band transmission or reception at 24 and 60 GHz. It can work completely in concurrent modes including single-band concurrent transmission and reception at 24 or 60 GHz and dual-band concurrent transmission and reception at 24 and 60 GHz. The developed T/R filter-switch makes possible simultaneous transmissions and receptions with a single antenna, which is desirable in RF systems yet not feasible with conventional T/R switches. Design 4 explains a 0.18-µm CMOS concurrent dual-band SPDT filter-switch operating over two distinctive wide bands around 24 and 60 GHz. In the on-state of the switch, the SPDT filter-switch is equivalent to a dual-band resonator. The concurrent dual-wideband SPDT filter-switch has a decent insertion loss, compact size, and good power handling capability.

The implementation of a continuous-time filter (CTF) useful for audio frequency applications is presented in this paper. The filter functions can be programmed and tuned with two independent control variables. The filter here proposed has been designed to work at 1.5 V of power supply and at a maximum of 0.5 /spl mu/A/OTA for the worst case current consumption. Electrical simulations of a Tow-Thomas biquad (TTB) show the possibility of obtaining low-pass and band-pass filter functions over the 10 Hz-40 kHz frequency range by changing a control current over four decades.

This paper describes the design of multifunction second order voltage-mode filter using the voltage differencing differential difference amplifier (VDDDA) as active element. The internal construction of VDDDA based on the 0.25um TSMC CMOS technology is used for simulation and testing. The proposed filter is sort of three inputs-single output (TISO) multifunction filter. It consists of single VDDDA, single resistor and two capacitors that is suitable to fabricate into monolithic chip. The filter can provide five standard functions namely, lowpass (LP), bandpass (BP), highpass (HP), band-stop (BS) and allpass (AP) responses, in the same circuit topology. Each filter response can be selected by digital method. The natural frequency and quality factor can be electronically tuned that is attractive for micro-computer or microcontroller controllability. The proposed filter was supplied by ±1.25 V source. The simulated results using PSpice simulation agree well with expected theoretical analysis.

Electronically tunable current-mode instrumentation amplifier with high CMRR and wide bandwidth

This paper presents a single VDTA based Mixed Mode type Biquad filter. The proposed Transadmittance Mode (TAM) type Biquad filter configuration employed single voltage differencing transconductance amplifier (VDTA) as an active building block, three passive element namely one grounded resistor, one grounded capacitor and one floating capacitor. The proposed transadmittance Mode multifunction Biquad filter configuration is presenting transadmittance mode type four basic standard filter functions low pass, high pass, band pass, band reject or band stop or band eliminate filter responses. These four type filter responses are realizing simultaneously with the selection of single input voltage signal. The proposed Transadmittance Mode multifunction Biquad filter configuration has more advantageous features such as low active and passive sensitivities, low power supply voltage, low power consumption, low quality factor, very low power consumption, more electronic tunability, higher linearity and required small area of the chip. The performance of the proposed configuration has been verified through PSPICE simulation using 0.18μm CMOS Technology process parameters.

Meminductor is a nonlinear two-terminal element with storage energy and memory ability. To date, meminductor element is not available commercially as memristor and memcapacitor are. Therefore, it is of great significance to implement a meminductor emulator for breadboard experiment. In this paper, a flux-controlled floating/grounded meminductor emulator without a memristor is presented. It is built with commercially available off-the-shelf electronic devices. It consists of single operational transconductance amplifier (OTA), single multiplier, two second-generation current conveyors (CCIIs), single current-feedback operational amplifier (CFOA) and single operational amplifier. Using OTA device introduces an additional control parameter besides frequency and amplitude values of applied voltage to control the area of pinched hysteresis loop of meminductor. Mathematical model of proposed emulator circuit is given to describe the behavior of meminductor circuit. The breadboard experiment is performed using CA3080, AD844, AD633J and LM741 for OTA, CCII–CFOA, multiplier and operational amplifier, respectively. Simulation and experimental test results are given to verify the theoretical analyses. Frequency-dependent pinched hysteresis loop is maintained up to 5 kHz. The presented meminductor emulator tends to work as ordinary inductor for higher frequencies.

Tunable Memristor Emulator using Off-The-Shelf components

This paper presents the second-order current-mode filter with 4 input currents and single output current. Five filter responses, namely High-pass (HP), Low-pass (LP), Band-pass (BP), Band-reject (BR) and All-pass (AP) filters are achieved. The pole frequency and quality factor are tuned by input bias current called electronic control. It has high output impedance which is able cascading in the current-mode filter and driving load without buffering devices. The filter uses only single active element namely current controlled current differencing transconductance amplifier (CCCDTA) and 2 grounded capacitors which is ideal for monolithic integrated circuit implementation. The filter was proved by Pspice simulation using BJT technology. The results are agreed with theoretical prediction.

In some applications of microgrids and distributed generation, it is necessary to feed islanded or stand-alone loads with high-quality voltage to provide low total harmonic distortion (THD). To fulfil these demands, an LC filter is usuallyconnected to the output terminals of power electronics converters. A cascaded voltage and current control loop with pulse-width modulation schemes are used to regulate the voltages and currents in these systems. However, these strategies have some drawbacks, particularly when multiple-input–multiple-output plants (MIMO) are controlled using single-input–single-output (SISO) design methods. This methodology usually produces a sluggish transient response and cross–coupling between different control loops and state variables. In this paper, a model predictive control (MPC) strategy based on the concept of optimal switching sequences (OSS) is designed to control voltage and current in an LC filter connected to a three-level neutral-point clamped converter. The strategy solves an optimisation problem to achieve control of the LC filter variables, i.e., currents and output voltages. Hardware-in-the-loop (HIL) results are obtained to validate the feasibility of the proposed strategy, using a PLECS–RT HIL platform and a dSPACE Microlab Box controller. In addition to the good dynamic performance of the proposed OSS–MPC, it is demonstrated using HIL results that the control algorithm is capable of obtaining low total harmonic distortion (THD) in the output voltage for different operating conditions.