scholarly journals A Novel Fully Differential Second Generation Current Conveyor and Its Application as a Very High CMRR Instrumentation Amplifier

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Soma Ahmadi ◽  
Seyed Javad Azhari

This paper aims to introduce a novel Fully Differential second generation Current Conveyor (FDCCII) and its application to design a novel Low Power (LP), very high CMRR, and wide bandwidth (BW) Current Mode Instrumentation Amplifier (CMIA). In the proposed application, CMRR, as the most important feature, has been greatly improved by using both common mode feed forward (CMFF) and common mode feedback (CMFB) techniques, which are verified by a perfect circuit analysis. As another unique quality, it neither needs well-matched active blocks nor matched resistors but inherently improves CMRR, BW, and power consumption hence gains an excellent matchless choice for integration. The FDCCII has been designed using 0.18 um TSMC CMOS Technology with ±1.2 V supply voltages. The simulation of the proposed FDCCII and CMIA have been done in HSPICE LEVEL 49. Simulation results for the proposed CMIA are as follow: Voltage CMRR of 216 dB, voltage CMRR BW of 300 Hz. Intrinsic resistance of X-terminals is only 45 Ω and the power dissipation is 383.4 μW.  Most favourably, it shows a constant differential voltage gain BW of 18.1 MHz for variable gains (here ranging from 0 dB to 45.7 dB for example) removing the bottleneck of constant gain-BW product of Voltage mode circuits.

2014 ◽  
Vol 530-531 ◽  
pp. 217-220
Author(s):  
Hwang Cherng Chow ◽  
Bing Shiun Tang

In this paper, a high performance current-mode instrumentation amplifier has been proposed with low noise, low power and high CMRR features. The proposed design can adjust the gain with an external resistor for the processing of various biomedical signals. To reduce the noise of the amplifier, two design methods including PMOS input and lateral pnp BJT input have been implemented to improve the prior arts. To meet the single power supply need, a biomedical voltage level shifter is also proposed for low cost CMOS implementation. Based on the post-layout simulation results, the presented current-mode amplifier achieves high CMRR over 120 dB, power consumption of 61 uW at 1.8-V supply using standard 0.18-um CMOS technology.


This article given a second generation current controlled current conveyor positive (CCCII+), second generation current controlled current conveyor negative (CCCII-), Quadrature oscillator with high-Q frequency choosing network and implementing completely different phase oscillators by employing (CCCII+) positive and (CCCII-) negative, and high band pass filter network, the approach is predicted on the CMOS technology . The root of this concept is, considering a customary voltage mode oscillator which consists of band pass filter with prime quality issue (high-Q) and voltage mode amplifier is transfigure into current mode oscillator by replacing tans-conductance amplifier. Because the loop of the oscillator is has lavish selectivity, the oscillator process less distortion. In addition 3dB bandwidth, oscillating condition, oscillation frequency of the oscillator could linearly, independently and electronically be tuned by adjusting the bias current of the (CCCII±)[1], lastly different simulations have been carried out to verify the linearity between output and input ports, range of frequency operations. These results can justify that the designed circuits are workable.


Author(s):  
Jitender Jitender ◽  
Jitendra MOHAN ◽  
Bhartendu CHATURVEDI

Two novel resistorless structures of a first-order voltage-mode all-pass filter are presented in the paper. Both the structures employ a fully differential second-generation current conveyor (FDCCII) as the primary active element, in addition to an active resistor. A grounded capacitor is the only passive component used in both the structures. In both the structures, CMOS realization of FDCCII is utilized; hence, these structures are CMOS compatible. Some of the other highly demanded features possessed by the presented all-pass structures are: a simple circuit topology, electronic tunability, high input impedance, constraint-free operation in terms of passive component matching, and low sensitivity figures. The theoretical performances under ideal and non-ideal scenarios are presented in detail. Furthermore, the proposed idea is extended to an Nth-order voltage-mode all-pass filter and a quadrature oscillator to explore some of the possible applications. PSPICE simulation results verify the theoretical claims of the presented all-pass filters. HIGHLIGHTS Two novel resistorless structures of first-order all-pass filters based on fully differential second-generation current conveyor are presented Performance of the proposed structures are thoroughly described in ideal and non-ideal scenarios Theoretically described details of the proposed structures are verified by carrying simulations on PSPICE using 180 nm CMOS technology An Nth-order all-pass filter and a quadrature oscillator are also presented as applications GRAPHICAL ABSTRACT


2017 ◽  
Vol 26 (11) ◽  
pp. 1750169 ◽  
Author(s):  
Francesco Centurelli ◽  
Pietro Monsurrò ◽  
Gaetano Parisi ◽  
Pasquale Tommasino ◽  
Alessandro Trifiletti

This paper presents a fully differential class-AB current mirror OTA that improves the common-mode behavior of a topology that presents very good differential-mode performance but poor common-mode rejection ratio (CMRR). The proposed solution requires a low-current auxiliary circuit driven by the input signal, to compensate the effect of the common-mode input component. Simulations in 40-nm CMOS technology show a net reduction of common-mode gain of more than 90[Formula: see text]dB without affecting the differential-mode behavior; a sample-and-hold amplifier exploiting the proposed amplifier has also been simulated.


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