Evaluation of modern MOSFET models for bulk-driven applications

With the breathtaking advance of technology, the modern analog/mixed-signal design needs to consider the requirements of low voltage/power and the effects of the MOSFET channel length shrinking. Although a few different schemes have been proposed, the bulk-driven technique, which uses bulk terminal (the fourth terminal of a MOSFET) for signal input, is a promising solution to the low-voltage and low-power applications. However, the conventional MOSFET models are normally set up for the typical gate-driven applications (i.e., using gate terminal for signal input). Besides, due to shrinking MOSFET channels, those MOSFET models may not perform correctly and accurately for the bulk-driven applications, especially in the moderate inversion region. In this paper, we evaluate two MOSFET models including BSIM3V3 and EKV for the bulk-driven applications in a sub-micron CMOS technology. BSIM3V3 is a widely used model in the semiconductor industry, while the EKV model is suitable for the small-channel-length simulation. We focus on several critical MOSFET parameters for bulk-driven application and conduct thorough experiments using the two aforementioned models. The simulation results are analyzed to demonstrate the advantages of the bulk-driven technique compared to the gate-driven scheme in the low-voltage/low-power applications. Finally the performance of the two MOSFET models in the bulk-driven applications is summarized.