Subthreshold conduction

thumbnail|Subthreshold leakage in an nFET

Subthreshold conduction or subthreshold leakage or subthreshold drain current is the current between the source and drain of a MOSFET when the transistor is in subthreshold region, or weak-inversion region, that is, for gate-to-source voltages below the threshold voltage.

In digital circuits, subthreshold conduction is generally viewed as a parasitic leakage in a state that would ideally have no conduction. In micropower analog circuits, on the other hand, weak inversion is an efficient operating region, and subthreshold is a useful transistor mode around which circuit functions are designed.

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