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In this article, we propose a novel high-performance complementary metal oxide semiconductor (CMOS) current differencing transconductance amplifier (CDTA) with a transconductance gain (GM) that can be linearly tuned by a voltage. By using a high-speed, low-voltage, cascaded current mirror active resistance compensation technique, the proposed CDTA circuit exhibits wide frequency bandwidths, high current tracking precisions as well as large output impedances. The linear-tunableGMof the CDTA is designed with the use of linear composite metal oxide semiconductor field-effect transistor as basic cells in the circuit. Combining these two approaches, several design concerns are studied, including: impedance characteristic, tracking errors, offset and linearity and noise. The prototype chip with a 0.25 mm2area is fabricated in aGlobalFoundries’0.18 μmCMOS process. The simulated results and measured results with ±0.8 V DC supply voltages are presented, and show extremely wide bandwidths and wide linear tuning range. In addition, a fully differential band-pass filter for a high-speed system is also given as an example to confirm the high performance of the proposed circuit. [ABSTRACT FROM AUTHOR]

In this paper, a novel $$\pm $$ 0.8V current differencing transconductance amplifier (CDTA) with programmable and tunable ability is proposed and analyzed. The digitally programmable CDTA is built around a lot of programmable current mirror arrays and three linear tunable transconductors, which contains separate analog and digital tuning feature. Moreover, a CDTA-based general sinusoidal signal generator circuit with two fixed-value capacitors and two grounded resistors is presented here. The generator circuit can be configured to perform the following signal modulation techniques: amplitude modulation, frequency modulation, amplitude shift keying, frequency shift keying, phase shift keying, and quadrature amplitude modulation. Cadence Virtuoso Analog Design Environment using GlobalFoundries' 0.18 um CMOS process is used to develop the generator circuit and verify the theory by the post-layout simulations. [ABSTRACT FROM AUTHOR]