At what range the PLL can maintain?

At what range the PLL can maintain?

At what range the PLL can maintain the lock in the circuit? Explanation: The change in frequency of the incoming signal can be tracked when the PLL is locked. So, the range of frequencies over which PLL maintains the lock with the incoming signal is called as the lock in range. 7.

What is tracking range of PLL?

Lock range (and hold range) shows how far the PLL frequency can track an input signal. Capture range (and pull-in range) shows how far from the free running frequency the VCO will move to lock onto an input signal.

Why capture range is less than lock range in PLL?

As shown in the fig-2, it is much narrower compare to the PLL lock range. Both PLL lock range and PLL capture range are centered around the VCO free running frequency. PLL acts as a Band Pass Filter which is effective in eliminating the noise as well as interference from the input signal if present.

What is cycle slip in PLL?

When the PLL is locked, you expect the number of ref and fbclk cycles to be equal. When one is greater than the other, then you are experiencing cycle slips. If the PLL is initially locked, then cycle slips occur for three reasons: 1) the reference modulates frequency or phase faster than the PLL can respond.

What is meant by lock range?

lock-in range: 1. The range of frequencies within which a closed-loop system can aquire and track a signal. (188) 2. The dynamic range within which a closed-loop system can aquire and track a signal.

What are the advantages of using PLL?

A high bandwidth allows the PLL to track jitter, whereas a low bandwidth filters out high-frequency jitter. A high-bandwidth PLL also provides a fast lock time but allows more jitter to flow through. A low-bandwidth PLL, on the other hand, filters out more jitter, but increases lock time.

What is Spur in PLL?

These spurs are commonly referred to as reference spurs, though reference here does not mean the reference clock frequency. Rather, it refers to fPFD. An LO signal produced by an integer-N PLL has dual sideband spurs at fPFD and its harmonics.

What makes the PLL initially not in lock?

When the PLL is initially not in lock, what frequency range can make the PLL lock is the capture range. Lock range is the parameter you should be interested in if you are looking for it’s tracking behavior.

What is the capture range of a PLL?

Capture range is defined as the band of frequencies centered around the VCO natural frequency where the PLL can initially establish or acquire frequency lock with an external input signal from an unlocked condition. Quote1: In modern PLLs capture range and lock range are the same. But by definition these are different

Which is greater the lock range or the capture range?

Always lock range is equal to or greater than the capture range. Lock range is defined as the band of frequencies centered on the VCO’s natural frequency over which a PLL can maintain frequency lock with an external input signal.

Where does the lock range start and end?

There, you might call the “lock in range” starting and ending halfway to the two adjacent comb teeth, where the capture range can, with coarse tuning, be the entire possible output bandwidth. Once the PLL is in lock, what is the input (or VCO) frequency range for which it can keep itself locked is the lock range.