+1 vote
in Linear Integrated Circuits by (37.1k points)
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

The question was asked in an interview for internship.

My question comes from Operational Amplifier Internal Circuit topic in section Operational Amplifier of Linear Integrated Circuits

1 Answer

0 votes
by (39.8k points)
Right option is (a) 4VT < Vd < -4VT

Delve into insight with: 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.

Related questions

We welcome you to Carrieradda QnA with open heart. Our small community of enthusiastic learners are very helpful and supportive. Here on this platform you can ask questions and receive answers from other members of the community. We also monitor posted questions and answers periodically to maintain the quality and integrity of the platform. Hope you will join our beautiful community