Self-Bias:

This is most common method for biasing the JFET. Self bias circuit for N channel JFET is shown in the figure.

Since no gate current flows through reverse-biased gate-source, the gate current I_G = 0 and, thus, v_G = i_G R_G = 0

The gate source voltage can be given by

V_Gs = V_G - V_s = 0 - I_D R_s = - I_D R_s

So voltage drop across the resistance R_s provides biasing voltage V_Gg and no external source is required for the biasing and this is reason that it is called as self-biasing.

The operating point can easily be determined from the equation given below :

V_DS = V_DD - I_D (R_D + R_S)

Thus DC conditions of JFET amplifier are specified completely. Self biasing of a JFET stabilizes its quiescent operating point against any change in the parameters like transconductance. Let given JFET be replaced by another JFET having double conductance then drain current will also try to be double but since any increase in the voltage drop across R_s, thus, gate-source voltage, V_GS becomes negative and therefore increase in drain current is reduced.

Email based Electronics Devices and circuits assignment help - homework help at Expertsmind

Are you searching Electronics Engineering assignment help expert for help with JFET - Self-Bias questions?  JFET - Self-Bias topic is not easier to learn without any external help?  We at www.expertsmind.com offers free lecture notes for Electronics Devices and circuits assignment help and Electronics Devices and circuits homework help. Live tutors are available 24x7 hours for helping students in their JFET - Self-Bias related problems. We provide step by step JFET - Self-Bias question's answers with 100% plagiarism free content. We prepare quality content and notes for JFET - Self-Bias topic under Electronics Devices and circuits theory and study material. These are avail for subscribed users and they can get advantages anytime.

Why Expertsmind for assignment help

1. Higher degree holder and experienced experts network
2. Punctuality and responsibility of work
3. Quality solution with 100% plagiarism free answers
4. Time on Delivery
5. Privacy of information and details
6. Excellence in solving electronics engineering questions in excels and word format.
7. Best tutoring assistance 24x7 hours