The JFE150 functionality is identical to standard N-channel depletion JFET devices. The gate-to-source (V_GS) voltage, drain-to-source voltage (V_DS) and drain-to-source current (I_DS) determine the region of operation.

• For V_GS < V_GSC: JFE150 conduction channel is closed; I_DS is only determined by junction leakage current.
• For V_GS > V_GSC: Two modes of operation can exist depending on V_DS. When V_DS is less than the linear (saturation) region threshold (see Figure 9-2), the device operates in the linear region, meaning that the device behaves as a resistor connected from drain-to-source with minimal variation from any changes in V_GS. When V_DS is greater than the linear (saturation) region threshold, I_DS has a strong dependance on V_GS, where the relationship is described by the parameter gm.

Figure 8-1 V_DS vs I_DS