At what condition differential amplifier function as a switch
A. 4VT < Vd < -4VT
B. -2VT ≤ Vd ≤ 2VT
C. 0 ≤ Vd < -4VT
D. 0 ≤ Vd ≤ 2VT
Answer:A
At what condition differential amplifier function as a switch
A. 4VT < Vd < -4VT B. -2VT ≤ Vd ≤ 2VT C. 0 ≤ Vd < -4VT D. 0 ≤ Vd ≤ 2VT
Explanation: For Vd > 4VT, the output voltage are VO1 = VCC, VO2= VCC-αF IQRC. Therefore, a transistor Q1 will be ON and Q2 will be OFF. Similarly for Vd> -4VT, both transistors Q2 & Q1 will be ON.