A log-domain current-mode quadrature sinusoidal oscillator based on lossless integrators is prese... more A log-domain current-mode quadrature sinusoidal oscillator based on lossless integrators is presented. The circuit is a direct realization of a first-order differential equation for obtaining the lossy and lossless integrators. Each of the log-domain lossless integrators is realized by using only NPN transistors and a grounded capacitor for achieving low-power and fast response. The proposed oscillator uses two-lossless integrator loop which can be electronically tuned through bias currents. A validated BJT model which is used in SPICE simulation operated from a single power supply as low as 2.5 V. The oscillation frequency is controlled over four decades of frequency. The total harmonic distortions for two-phases QSO (12 MHz) is obtained around 0.93% which enables fully integrated in telecommunication systems. The proposed circuit is also suitable for high-frequency applications. Nonideality studies are included and PSpice simulation results confirm the theoretical results.
This research proposes bipolar junction transistor (BJT)-based log-domain high-order elliptic lad... more This research proposes bipolar junction transistor (BJT)-based log-domain high-order elliptic ladder low-pass (LPF) and band-pass filters (BPF) using a lossless differentiator and lossless and lossy integrators. The log-domain lossless differentiator was realized by using seven BJTs and one grounded capacitor, the lossy integrator using five BJTs and one grounded capacitor, and the lossless integrator using seven BJTs and one grounded capacitor. The simplified signal flow graph (SFG) of the elliptic ladder LPF consisted of two lossy integrators, one lossless integrator, and one lossless differentiator, while that of the elliptic ladder BPF contained two lossy integrators, five lossless integrators, and one lossless differentiator. Log-domain cells were directly incorporated into the simplified SFGs. Simulations were carried out using PSpice with transistor array HFA3127. The proposed filters are operable in a low-voltage environment and are suitable for mobile equipment and further ...
ABSTRACT This paper describes the design of a current-mode single-input multiple-output (SIMO) un... more ABSTRACT This paper describes the design of a current-mode single-input multiple-output (SIMO) universal filter based on the log-domain filtering concept. The circuit is a direct realization of a first-order differential equation for obtaining the lossy integrator circuit. Lossless integrators are realized by log-domain lossy integrators. The proposed filter comprises only two grounded capacitors and twenty four transistors. This filter suits to operate in very high frequency (VHF) applications. The pole-frequency of the proposed filter can be controlled over five decade frequency range through bias currents. The pole-Q can be independently controlled with the pole-frequency. Nonideal effects on the filter are studied in detail. A validated BJT model is used in the simulations operated by a single power supply, as low as 2.5 V. The simulation results using PSpice are included to confirm the good performances and are in agreement with the theory.
Proceedings of 2010 Ieee International Symposium on Circuits and Systems, 2010
ABSTRACT This paper describes the design of a current-mode universal filter based on log-domain f... more ABSTRACT This paper describes the design of a current-mode universal filter based on log-domain filtering concept. The circuit is a direct realization of a first-order differential equation for obtaining the two integrators loop structure. Lossless integrators are realized by log-domain lossy integrators. The proposed filter comprises only two grounded capacitors and sixteen transistors. Frequency response of the proposed filter can be instantaneously controlled over a very wide frequency range by controlling current. Quality factor is independently controlled by another current. It can be seen that the proposed circuit suites for high-frequency applications. A validated BJT model that used in simulation is operated by a single power supply as low as 2.5V. The wide-range frequency response is controlled over five decades of current controlled.
This paper presents the realization of CMOS-based current-mode Elliptic ladder band-pass filter b... more This paper presents the realization of CMOS-based current-mode Elliptic ladder band-pass filter by using doubly terminated Elliptic RLC ladder band-pass filter prototype [1], [2]. The proposed circuit contains lossless integrators, lossy integrators and multiple outputs current gains. The frequency response of the proposed circuit can be electronically tuned between 1 MHz and 100 MHz by adjusting bias current between 1μA and 1,000 μA. The proposed circuit uses 1.5 V power supply and 0.1 W power consumption. The passive elements that contained in the proposed filter are only grounded capacitors without using other passive elements that can make this filter suitable for integrated circuit. PSPICE simulation results are carried out by using TSMC 0.18 μm technology and agreed well with the theory.
Log-domain current-mode multiphase sinusoidal oscillators based on all-pass filters are presented... more Log-domain current-mode multiphase sinusoidal oscillators based on all-pass filters are presented in this paper. The first-order differential equation is used for obtaining inverting and non-inverting all-pass filters. The proposed oscillators are realized by all-pass filters whose natural frequency and stage gain can be electronically tuned by adjusting the bias currents. Each all pass filter contains 10 NPN transistors and a grounded capacitor. The validated BJT model which is used in SPICE simulation operated by a single power supply as low as 2.5 V. The frequency of oscillation can be controlled over four decades. The total harmonic distortions of these MSO at frequency 56.67 MHz and 54.44 MHz, obtained around 0.52% and 0.75%, respectively. The proposed circuits enable fully integrated in telecommunication systems and also suit to high-frequency applications. Nonideality studies and PSpice simulation results are included to confirm the theory.
This study describes the design of a multiphase sinusoidal oscillator (MSO) using CCCDTA-based al... more This study describes the design of a multiphase sinusoidal oscillator (MSO) using CCCDTA-based allpass filters with grounded capacitors. The oscillation condition and oscillation frequency can be electronically/orthogonal-ly controlled. The proposed MSO provides 2n (n 2) phase signals that are equally spaced in phase and equal ampli-tude. The circuit requires one CCCDTA, one electronic resistor and one grounded capacitor per phase and no additional current amplifier and floating elements. High output impedances of the configuration enable the circuit to be cascaded to the current-mode circuit without addi-tional current buffers. The effects of the non-idealities of the CCCDTA-allpass sections were also studied. The re-sults of PSPICE simulations using CMOS CCCDTA are presented, demonstrating their consistency with theoretical assumptions.
A log-domain current-mode quadrature sinusoidal oscillator based on lossless integrators is prese... more A log-domain current-mode quadrature sinusoidal oscillator based on lossless integrators is presented. The circuit is a direct realization of a first-order differential equation for obtaining the lossy and lossless integrators. Each of the log-domain lossless integrators is realized by using only NPN transistors and a grounded capacitor for achieving low-power and fast response. The proposed oscillator uses two-lossless integrator loop which can be electronically tuned through bias currents. A validated BJT model which is used in SPICE simulation operated from a single power supply as low as 2.5 V. The oscillation frequency is controlled over four decades of frequency. The total harmonic distortions for two-phases QSO (12 MHz) is obtained around 0.93% which enables fully integrated in telecommunication systems. The proposed circuit is also suitable for high-frequency applications. Nonideality studies are included and PSpice simulation results confirm the theoretical results.
This research proposes bipolar junction transistor (BJT)-based log-domain high-order elliptic lad... more This research proposes bipolar junction transistor (BJT)-based log-domain high-order elliptic ladder low-pass (LPF) and band-pass filters (BPF) using a lossless differentiator and lossless and lossy integrators. The log-domain lossless differentiator was realized by using seven BJTs and one grounded capacitor, the lossy integrator using five BJTs and one grounded capacitor, and the lossless integrator using seven BJTs and one grounded capacitor. The simplified signal flow graph (SFG) of the elliptic ladder LPF consisted of two lossy integrators, one lossless integrator, and one lossless differentiator, while that of the elliptic ladder BPF contained two lossy integrators, five lossless integrators, and one lossless differentiator. Log-domain cells were directly incorporated into the simplified SFGs. Simulations were carried out using PSpice with transistor array HFA3127. The proposed filters are operable in a low-voltage environment and are suitable for mobile equipment and further ...
ABSTRACT This paper describes the design of a current-mode single-input multiple-output (SIMO) un... more ABSTRACT This paper describes the design of a current-mode single-input multiple-output (SIMO) universal filter based on the log-domain filtering concept. The circuit is a direct realization of a first-order differential equation for obtaining the lossy integrator circuit. Lossless integrators are realized by log-domain lossy integrators. The proposed filter comprises only two grounded capacitors and twenty four transistors. This filter suits to operate in very high frequency (VHF) applications. The pole-frequency of the proposed filter can be controlled over five decade frequency range through bias currents. The pole-Q can be independently controlled with the pole-frequency. Nonideal effects on the filter are studied in detail. A validated BJT model is used in the simulations operated by a single power supply, as low as 2.5 V. The simulation results using PSpice are included to confirm the good performances and are in agreement with the theory.
Proceedings of 2010 Ieee International Symposium on Circuits and Systems, 2010
ABSTRACT This paper describes the design of a current-mode universal filter based on log-domain f... more ABSTRACT This paper describes the design of a current-mode universal filter based on log-domain filtering concept. The circuit is a direct realization of a first-order differential equation for obtaining the two integrators loop structure. Lossless integrators are realized by log-domain lossy integrators. The proposed filter comprises only two grounded capacitors and sixteen transistors. Frequency response of the proposed filter can be instantaneously controlled over a very wide frequency range by controlling current. Quality factor is independently controlled by another current. It can be seen that the proposed circuit suites for high-frequency applications. A validated BJT model that used in simulation is operated by a single power supply as low as 2.5V. The wide-range frequency response is controlled over five decades of current controlled.
This paper presents the realization of CMOS-based current-mode Elliptic ladder band-pass filter b... more This paper presents the realization of CMOS-based current-mode Elliptic ladder band-pass filter by using doubly terminated Elliptic RLC ladder band-pass filter prototype [1], [2]. The proposed circuit contains lossless integrators, lossy integrators and multiple outputs current gains. The frequency response of the proposed circuit can be electronically tuned between 1 MHz and 100 MHz by adjusting bias current between 1μA and 1,000 μA. The proposed circuit uses 1.5 V power supply and 0.1 W power consumption. The passive elements that contained in the proposed filter are only grounded capacitors without using other passive elements that can make this filter suitable for integrated circuit. PSPICE simulation results are carried out by using TSMC 0.18 μm technology and agreed well with the theory.
Log-domain current-mode multiphase sinusoidal oscillators based on all-pass filters are presented... more Log-domain current-mode multiphase sinusoidal oscillators based on all-pass filters are presented in this paper. The first-order differential equation is used for obtaining inverting and non-inverting all-pass filters. The proposed oscillators are realized by all-pass filters whose natural frequency and stage gain can be electronically tuned by adjusting the bias currents. Each all pass filter contains 10 NPN transistors and a grounded capacitor. The validated BJT model which is used in SPICE simulation operated by a single power supply as low as 2.5 V. The frequency of oscillation can be controlled over four decades. The total harmonic distortions of these MSO at frequency 56.67 MHz and 54.44 MHz, obtained around 0.52% and 0.75%, respectively. The proposed circuits enable fully integrated in telecommunication systems and also suit to high-frequency applications. Nonideality studies and PSpice simulation results are included to confirm the theory.
This study describes the design of a multiphase sinusoidal oscillator (MSO) using CCCDTA-based al... more This study describes the design of a multiphase sinusoidal oscillator (MSO) using CCCDTA-based allpass filters with grounded capacitors. The oscillation condition and oscillation frequency can be electronically/orthogonal-ly controlled. The proposed MSO provides 2n (n 2) phase signals that are equally spaced in phase and equal ampli-tude. The circuit requires one CCCDTA, one electronic resistor and one grounded capacitor per phase and no additional current amplifier and floating elements. High output impedances of the configuration enable the circuit to be cascaded to the current-mode circuit without addi-tional current buffers. The effects of the non-idealities of the CCCDTA-allpass sections were also studied. The re-sults of PSPICE simulations using CMOS CCCDTA are presented, demonstrating their consistency with theoretical assumptions.
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