JFET Buffer Bias Calculator

A JFET buffer (Common Drain Amplifier) is useful in that it has extremely high input resistance as compared to a BJT buffer. The input resistance is equal to RG, which is typically very large, on the order of 1M ohm.

Figure 1 - N-Channel JFET Buffer

Equations:

I_DS= I_DSS(1-V_GS/Vp)²

RS= V_RS/I_DS