For the collector-feedback configuration of Fig. 4.129, determine:
a. IB.
b. IC.
c. VC.
FIG. 4.129
Refer Figure \(4.129\) from the textbook.
(a)
Base current is determined as follows:
$$ I_{B}=\frac{V_{C C}-V_{B E}}{R_{B}+\beta\left(R_{C}+R_{E}\right)} $$
Substitute the corresponding values to obtain \(I_{B}\).
$$ \begin{aligned} I_{B} &=\frac{16 \mathrm{~V}-0.7 \mathrm{~V}}{270 \mathrm{k} \Omega+(120)(3.6 \mathrm{k} \Omega+1.2 \mathrm{k} \Omega)} \\ &=18.09 \mu \mathrm{A} \end{aligned} $$
Hence, the base current is \(18.09 \mu \mathrm{A}\).
(b)
Collector current is determined as follows:
$$ I_{C}=\beta I_{B} $$
Substitute the corresponding values in the equation.
$$ \begin{aligned} I_{C} &=(120)(18.09) \\ &=2.17 \mathrm{~mA} \end{aligned} $$
Hence, the corresponding value of current \(I_{C}\) is \(2.17 \mathrm{~mA}\).
(c)
Voltage \(V_{C}\) is determined as follows:
$$ V_{C}=V_{C C}-I_{C} R_{C} $$
Substitute the corresponding values in the equation.
$$ \begin{aligned} V_{C} &=16 \mathrm{~V}-(2.17 \mathrm{~mA})(3.6 \mathrm{k} \Omega) \\ &=8.19 \mathrm{~V} \end{aligned} $$
Hence, the corresponding value of voltage \(V_{C}\) is \(8.19 \mathrm{~V}\).