Discussion
What does the tail current source do for a differential pair?
Answer: D
A high-impedance tail fixes the sum of the two collector currents, so a common-mode input moves both devices together without changing anything at the outputs. The differential gain is set by the transconductance and the collector loads, base bias comes from the source impedance, and filtering is a separate function. Since the tail's impedance is what makes the common-mode gain small, it is the component that decides the rejection ratio. Checking the units of each quantity catches a wrong formula before the arithmetic begins.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development