Chapter 4
Q. 4.6
The drain-feedback biased amplifier of Fig. 4-9(a) has the circuit element values of Example 4.5 except that the MOSFET is characterized by the parameter values of Example 4.4. Apply SPICE methods to determine the quiescent values.
Step-by-Step
Verified Solution
The netlist code below describes the circuit.
| Ex4_6.CIR – Drain-feedback bias vi 1 0 0V ; Value inconsequential CC 1 2 100uF; Value inconsequential RF 2 3 50MEGohm RL 3 4 3kohm VDD 4 0 15V M 3 2 0 0 NMOSG .MODEL NMOSG NMOS (Vto=4V Kp=0.0008ApVsq + Rd=1ohm Rg=1kohm) .DC VDD 15V 15V 1V .PRINT DC ID(M) V(2) V(3) .PROBE .END |
Execute 〈Ex4_6.CIR〉 and poll the output file to find I_{DQ} = ID(M) = 2.79 \text{mA}, V_{DSQ} = V(3) = V_{GSQ} = V(2) = 6.64 \text{V}.