Discussion
According to transfer characteristics of XLL the phase error between VCO output and incoming signal must be maintained between............ in order to maintain a lock.
Answer: A
The phase error must stay between 0 and π.
In a phase locked loop, the phase detector converts the phase difference between the VCO output and the incoming signal into a control voltage. For the common XOR-type detector, the average output rises linearly as the phase error goes from 0 to \(\pi\) and then falls again from \(\pi\) to \(2\pi\). The loop can correct the VCO only while the error stays on the rising part, 0 to \(\pi\), with the locked operating point normally near \(\pi/2\).
Outside that range the slope reverses, so the feedback has the wrong sign and lock is lost. The ranges 0 to \(\pi/2\), 0 to \(2\pi\) and \(\pi\) to \(2\pi\) are not the monotonic range of that characteristic.
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