A novel ±0.8 V high-performance voltage-tunable CDTA with enhanced bandwidth

Abstract

In this article, we propose a novel high-performance complementary metal oxide semiconductor (CMOS) current differencing transconductance amplifier (CDTA) with a transconductance gain (G_M) 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-tunable G_M of 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 mm² area is fabricated in a GlobalFoundries’0.18 μm CMOS 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.

Keywords:

• CDTA
• low voltage
• bandwidth enhancement
• linear-tunable
• noise

Acknowledgements

The authors thank the authors whose works have been cited throughout the article. The authors also thank the individuals who reviewed this article and gave their valuable comments.

ORCID

Zanming Xia http://orcid.org/0000-0003-0904-8855

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 61274020].