Exam Questions Papers - Engineering

Q1:

A bipolar differential amplifier uses a transistor having β0 = 200, ICQ = 100 mA, |Adm| = 500 and CMRR = 80 dB. The value of Rc and RE will be respectively __________ .

A 1.25 kΩ, 1.25 MΩ

B 125 kΩ, 1.25 MΩ

C 1.25 MΩ, 1.25 kΩ

D 3.25 kΩ, 3.25 MΩ

ANS:A - 1.25 kΩ, 1.25 MΩ

80 = 20 log CMRR CMRR = 10000 But CMRR = 2gmRE = 1.25 MΩ Adm = - gmRC = 1.25 KΩ.