Conference Paper

High-gain current amplifiers for low-power MOSFET-C filters

Department of Electrical Engineering, Prince of Songkla University, Amphoe Muang Songkhla, Songkhla, Thailand
DOI: 10.1109/ISCAS.2006.1692621 Conference: Circuits and Systems, 2006. ISCAS 2006. Proceedings. 2006 IEEE International Symposium on
Source: IEEE Xplore


Current amplifiers have been proposed as alternatives for low-power MOSFET-C or active-RC filters. High gain of the proposed current amplifiers relies on internal high impedance nodes. Such high impedance is realised using positive feedback cross-coupling configuration to cancel its negative feedback counterpart. Two different output stages, namely class-A and class-AB are also introduced. Bias circuits suitable for the proposed amplifiers are also introduced where they further help minimise power consumption and silicon area in a high-order filter design. The proposed circuits employed in a simple second-order filter were compared with a conventional folded-cascode OTA amplifier under 1-V supply. Simulation results with 0.18mum CMOS process indicate correct functionalities and superior linearity performance offered by the proposed amplifiers

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Available from: Phanumas Khumsat, Aug 27, 2014
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    • "Consequently, a current amplifier play very important role in current-mode signal processing circuits/systems. The applications of the current amplifiers can be found in filters [4] [5], oscillators [6] [7], automatic gain control (AGC) [8] [9], sensors [10] [11] [12], and etc. [13] [14] [15] [16]. Besides using transistor-level design [17] [18] [19] [20] [21], the realizations of current amplifiers can be popularly accomplished by employing building blocks such as operational transconductance amplifiers (OTA) [22] [23], current operational amplifier (COA) [24] [25] [26], "
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    ABSTRACT: This article proposes a novel topology for implementation of a simple current amplifier using only single current controlled current conveyor transconductance amplifiers (CCCCTA). The features of the proposed configuration are that: its current gain can be controlled by input bias currents; the proposed circuit is low temperature sensitive, the circuit description is very simple. The circuit performances are depicted trough PSPICE simulations, they show good agreement to theoretical anticipation and provide ability to measure small resistance changes at a wide range of frequency (more than 167MHz). The power consumption is approximately 1.39mW at ±1.5V supply voltages.
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    ABSTRACT: This paper presents a new low-voltage and low-power amplifier based on the class-AB differential log-companding technique. The circuit has been designed using a 0.25 m CMOS process. The proposed amplifier consumes less than 3.2 W from 0.6 V supply voltage at the maximum input current. The CMRR of this circuit is 35.76 dB; thus, it has very high performance in eliminating the common mode signal. The presented technique can be applied to many applications, such as filter, reference voltage, rectifier, etc.