Positive SSL
1 如圖所示,RB1 = 12kΩ、RB2 = 4kΩ、RE = 1kΩ、RL = 8Ω、N1 : N2 = 1 : 2、N3 : N4 = 1 : 15,β = 100,rπ = 2kΩ,求 |Av| ?
A 90
B 100
C 180
D 300

`R_L`=8Ω

變壓器 阻抗與匝數平方正比

從變壓器N3看進去的阻抗:

`15^2*8` = 1.8kΩ

變壓器 電壓與匝數成正比

輸入變壓器匝數比 1:2

`V_i` 先放大 2 倍 再進入電晶體放大

`|A_v|` = ` 2* (i_c*1.8k) / (i_b*2k)`

= ` 2* (100*i_b*1.8k) / (i_b*2k)`

= ` 2* (100*1.8k) / (2k)`

= 180