constant-current threshold voltage (V_T(ci))

The gate-source voltage at which the drain current is equal to a constant current, appropriate for a given technology, times the ratio of gate width (W) to gate length (L). V_T(ci) can be calculated using

V_T(ci) = V_GS (at I_D = I_D0 W/L)

where

W and L are the gate width and gate length as printed on the wafer;

I_D0 is selected for a given technology such that V_T(ci) is in the subthreshold region of the device. For N-MOSFET devices, JESD28-A suggests 0.1 μA; for P-MOSFET devices, JESD60 suggests -0.025 μA.

References