FET Buffer Deviation Calculator

VDD (V)
Desired V size=2>RS (V)
Vpor VGS(off) (Pinch off Voltage, negative) (V)
IDSS (Zero Gate Voltage Drain Current) (mA)

IDS (mA)
RS (Ω)
VGS (V)

Equations:

IDS= IDSS(1-VGS/Vp)2

RS= VRS/IDS

VGS is called the gate-source cutoff voltage or cutoff voltage, and is represented by VGS (off). In the case of n-channel JFET, the VGS (off) value has a negative sign. It is difficult to measure the VGS of the actual JFET corresponding to ID = 0. When using a small signal JFET in an amplifier, the VGS reaching ID = 0.1-10μA is often defined as VGS (off).