作者fairwarning (一輪明月與藍夜!!)
看板Grad-ProbAsk
標題[理工] [電子]-BJT差動
時間Wed Sep 16 12:28:59 2009
[題目]
A BJT differential amplifier having the biasing circuit with
current source found to have an input resistance if 10KΩ and
a voltage gain of 100 with the output taken differentially between
collector resistors of 5KΩ.
What is the bias current for the amplifier and β for the transistor used?
請問
我把上述文字變成電路圖這樣畫對嗎?
http://www.wretch.cc/album/show.php?i=fairwarning&b=73&f=1071626626&p=2
又請問
a voltage gain of 100 with the output taken differentially between
collector resistors of 5KΩ.
這句話的意思是Vo在Rc那兩端輸出(得到Av)? 請問這樣翻譯對嗎?
[我的解題過程]
Ri=2rπ=10K -------> rπ=5K
rπ=(1+β)re , re=Vt/IE -----> re=0.505mA
乘上2邊 所以 current source = 1.01mA
又Ad(雙)=gm*Rc
100 = gm * 5 又 β=gm*rπ -----> β=100
請問上述解法對嗎? 在算電壓增益時...不用算Acm嗎??
還請大家幫忙檢查與解析..
謝謝大家的幫忙!! 謝謝!!
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◆ From: 140.127.150.126
※ 編輯: fairwarning 來自: 140.127.150.126 (09/16 12:32)
1F:推 jamtu:增益為什麼要算Acm ? 09/16 14:48
2F:→ jamtu:Acm是有mismatch才要算的東西吧 ~~ 09/16 14:50
3F:→ fairwarning:謝謝告知!! ^^ 09/16 16:32