Electronic Devices - BJT Amplifiers - Discussion
Discussion Forum : BJT Amplifiers - General Questions (Q.No. 21)
21.
Refer to this figure. Calculate the value of Rin(tot).
37.7 k
3.77 k
378
2.25 k
Discussion:
6 comments Page 1 of 1.
Charl said:
8 years ago
re' = 26mV (voltage @ room temp) divided by Ie.
Ie = (Vb - Vbe) / RE = (3.7V - 0.7)/500
Get the value of Vb by using voltage divider equation.
Ie = (Vb - Vbe) / RE = (3.7V - 0.7)/500
Get the value of Vb by using voltage divider equation.
(4)
Divya said:
8 years ago
How to find the RE?
Fibo said:
9 years ago
Where did you get the value of r'e?
(1)
Tuan Tieu said:
1 decade ago
Without bypass capacitor, we have:
Rin(base) = beta x (r'e + RE ) = 100 x (6 + 500) = 50k.
Rin(total) = R1 || R2 || Rin(base) = 3.767 kOhm.
Rin(base) = beta x (r'e + RE ) = 100 x (6 + 500) = 50k.
Rin(total) = R1 || R2 || Rin(base) = 3.767 kOhm.
(1)
Anil from iiit basar,civil said:
1 decade ago
Zi = RB||Zb where Zb = beta.re+(1+beta)RE
Zb = (100*4.34)+(1+100)*0.5= 486k ohms
Zi = 4.07k || 486k = 3.77k ohms.
Zb = (100*4.34)+(1+100)*0.5= 486k ohms
Zi = 4.07k || 486k = 3.77k ohms.
(2)
K.REKHA said:
1 decade ago
Because range of out put impedance is 40 kilo ohms to 50 kilo ohms. So above options which value is nearer to the resistance that is correct answer.
(1)
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