• Clarification - The question (a) should read as:
(a) Find the minimum required $I_Q$ and the \"maximum\" value of R.
• Note - For all the questions, do NOT ignore the base current.
8.19 The circuit parameters for the class-A emitter follower shown in Figure
P8.16 are $V^+ = 24 V$, $V^- = -24 V$, and $R_L = 200 \Omega$. The transistor para-
meters are $\beta = 50$, $V_{BE(on)} = 0.7 V$, and $V_{CE(sat)} = 0.2 V$. The output
voltage is to vary between $+20 V$ and $-20 V$. The minimum current in $Q_1$
is to be $i_{E1} = 20 mA$. (a) Find the minimum required $I_Q$ and the minimum
value of R. (b) For $v_o = 0$, find the power dissipated in the transistor $Q_1$
and the power dissipated in the current source ($Q_2$, $Q_3$, and R). (c) Deter-
mine the conversion efficiency for a symmetrical sine-wave output voltage
with a peak value of 20 V.
$V^+ = 5 V$
$v_I$
$Q_1$
$i_{E1}$
$R = 1 k\Omega$
$Q_3$
$Q_2$
$V^- = -5 V$
Figure P8.16
$i_L$
$i_Q$
$v_o$
$R_L = 1 k\Omega$
