Hello guys, this is my very first question.
This is a part from a BJt audio amplifier volume control with 3 stages (Pre-amplifier,Buffer, & Power amplifier). This is the power amplifier stage.
I am asked to design the resistors RB3b & RB3a to provide a bias current of Ic=(375/20) mA when the input and output terminals are open circuits and to get Rin.
I proceeded in the problem,The voltage drop between the two diodes is 1.4V so I found that the voltage drop between each resistor is 3.8V and Vce for each transistor is 4.5V.
The problem is I cannot find beta (current gain) from the data sheet to deduce Ib and the current in the resistors. the date sheet provide beta for maximum of Vce=1V so I am stuck.
plus I read that the current in the resistors should be 10 Ib, is that right? I would appreciate any help, thank you.