Multi-valued logic (MVL) offers reduced circuit complexity and lower power consumption compared to binary logic, providing a pathway to higher information density. In this study, we report a ternary inverter circuit composed of an n-type electrolyte-gated transistor (EGT) paired with a heterojunction organic EGT exhibiting negative differential transconductance (NDT). This configuration creates asymmetric carrier injection, resulting in a distinct “N-shaped” transfer characteristic using a high-capacitance ionogel dielectric. We further systematically investigate how the thickness ratio between the p-type and n-type semiconductors modulates the NDT performance. Consequently, the integrated device successfully demonstrates three stable operating regimes, logic ‘0’, ‘1’, and ‘2’, highlighting its potential for high-density, low-power organic logic circuits.