1 如圖所示，一個兩級串接直接耦合放大器，其中VCC = 10.7V、RB1 = 100kΩ、RC1 = 1kΩ、RE1 = 1kΩ、RC2 = 0.5kΩ、RE2 = 1kΩ，假設電晶體Q1、Q2之共射極電流增益分別為99、48，且Q1、Q2之BE接面的切入電壓均為0.7V，計算此電路之直流偏壓，請問 IB1、IB2分為多少?(93統測)
A IB1 = 0.05mA，IB2 = 0.101mA
B IB1= 0.05mA，IB2 = 10mA
C IB1=0.1mA，IB2 = 0.101mA
D IB1= 0.1mA，IB2 =0.101mA
Q1電晶體:
`I_(B1)`*100k+0.7+`I_(E1)`*1k = 10.7
`I_(B1)`*100k+`I_(B1)`*(99+1)*1k = 10
200k`I_(B1)` = 10
`I_(B1)` = 10/200k = 0.05mA
Q2電晶體:
流過 `R_(C1)` 電阻的電流 = `I_(C1)+I_(B2)`
`(I_(C1)+I_(B2))*1k+0.7+I_(E2)*1k` = 10.7
`(99*I_(B1)+I_(B2))*1k+0.7+(48+1)*I_(B2)*1k` = 10.7
`4.95+I_(B2)*1k+49k*I_(B2)` = 10
`50k*I_(B2)` = 5.05
`I_(B2)` = 5.05/50k = 0.101mA
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