Exploring Charge-Based Mosfet Compact Models with ACM-2 as a Design-Oriented Paradigm

Charge-based MOSFET compact models provide a physically consistent framework to describe transistor charges and capacitances across operating regimes. Unlike current-based approaches, they enforce charge conservation and yield reliable predictions of dynamic and RF behavior. This paper reviews the main charge-based formulations, ranging from industrial standards (BSIM, PSP, HiSIM) to academic compact models such as EKV and the recent ACM-2 five-parameter approach. We contrast their philosophies, complexity, and accuracy, highlighting the trade-offs between highly parameterized industrial models and compact analytical formulations oriented to design and education. Representative applications in analog/RF design, digital timing and power estimation are discussed. Particular attention is given to the lightweight ACM-2 model as a paradigmatic example of simplicity and analytical clarity. We conclude by outlining current challenges-advanced device architectures, quantum effects, and automated parameter extraction-and perspectives for future compact modeling in deeply scaled technologies.