a class-AB power amplifier is to be designed for a 6.0W, 12
load. Darlington power transistors with 
=1250 and rated at 19W for 
=150 C, are available. A diode biasing network with diodes of junction size 1/20 that of the power transistors is to be used to give class AB operation.
a) What is the optimum 
and <
(max)>?
b) if we require that the currect through the diodes vary by no more than a factor of 6, what 
(current source) is necessary and what 
results?
c) Suppose that the only power supply available has Vs = ±15V. VL(Max) does not change, and neither does the Ibias requirement. But VL(worst), PD(worst, classB) , and PDQ do. What are their values?
D) What is 
(worst,total)?
e) What size heat sinks 
are needed for each transistor if we require a safety margin 
= 25 C
