# Question 3.7: For the transistor circuit of Fig. 3-8(a), R1 = 1 kΩ, R2 = 2......

For the transistor circuit of Fig. 3-8(a),  $R_1 = 1 kΩ, R_2 = 20 kΩ, R_C = 3 kΩ, R_E = 10 Ω$, and $V_{CC} = 15 \text{V}$.    If the transistor is the generic npn transistor of Example 3.3, use SPICE methods to determine the quiescent values $I_{BQ}, V_{BEQ}, I_{CQ}$, and $V_{CEQ}$.

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The netlist code below models the circuit.

 EX3_7.CIR – CE quiescent values R1     0 1 1kohm R2    2 1 20kohm RC    2 3 3kohm RE    4 0 10ohm VCC  2 0 15V Q 3 1 4 QNPNG .MODEL QNPNG NPN(Is=10fA Ikf=150mA Isc=10fA Bf=150 + Br=3 Rb=1ohm Rc=1ohm Va=30V Cjc=10pF Cje=15pF) .DC VCC 15V 15V 1V .PRINT DC IB(Q) IC(Q) V(1,4) V(3,4) .END

Execute 〈Ex3_7.CIR〉 and poll the output file to find

 VCC               IB(Q)             IC(Q)             V(1,4)             V(3,4) 1.500E+01      1.428E-05     2.575E-03     6.748E-01      7.252E+00

where $I_{BQ} = IB(Q), I_{CQ} = IC(Q), V_{BEQ} = V(1, 4),$ and $V_{CEQ} = V(3, 4)$.

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