Question

What is the minimum value of ß that makes Rin(base) ≥ 10R2 ? Given : Rc = 1.5kΩ, Vcc = 15V, RE = 680kΩ, R1 = 22kΩ, R2 = 4.7kΩ, ẞ = 150.

Answer 1

$\beta_{DC(min)}R_E=10R_2$

$\beta_{DC(min)}=\frac{10R_2}{R_E}=\frac{47k\varOmega}{680\varOmega}=69.1$

Answer = 69.1