Introducing a negative transconductance (NTC) regime into a switching curve of a field-effect transistor is a promising approach to overcome the fundamental limit of traditional digital logic circuits. However, the operation of NTC devices is only weakly conceptualized up to the present. This study proposes a drastically new way of regarding an NTC transistor as a functional equivalent of three interconnected normal field-effect transistors. The electrical model is directly inspired by the structural and materials characteristics of high-performance organic devices, and it is fully confirmed by measured experimental data. This finding, therefore, rationalizes that the NTC transistors have a unique potential to greatly reduce the transistor count in an integrated circuit, and offers a simple yet universal tool for systematic design and optimization of NTC transistor circuits through simulation-driven engineering.