[理工] [電子]-電流鏡

[fairwarning (一輪明月與藍夜!!)]

[電路圖]
http://www.wretch.cc/album/show.php?i=fairwarning&b=4&f=1893012287&p=0

[題目]
For the current mirror,the two BJTs are idential expect that the emitter area
of Q2 is three times of that of Q1.
Assume that Q2 is active , Vbe=0.6V , and the Early voltage is infinite;
(1)if β=∞ ,IL=?
(2)if β=10 ,IL=?

[解答]
(1) IL=0.6mA    (2) IL=0.428mA


為了增加題目文完整度...順便打(1)打出..

請問大家(2)要怎麼解呢?

謝謝大家的幫忙~~ 謝謝!



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吉他演奏曲
http://blog.xuite.net/iloveguitar/music?st=c&re=list&p=1&w=641095

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※ 發信站: 批踢踢實業坊(ptt.cc) 
◆ From: 140.127.150.126
推 eageoneal:列兩端BASE電流 右邊為左邊3倍 再利用IC=BIB 列方程式
→ eageoneal:設左邊IB為X 右邊IB為3倍X 中間為3+1=4X 左邊IC為 10X
→ eageoneal:{5-(-4.4)}/47=14X X=0.0142mA 鎖球極為右邊IC=30X=
→ eageoneal:=0.42857...mA
→ fairwarning:謝謝喔..我自己試試看!!