Fast locking PLL for frequency hopping system

[jihrenee]

I'm currently doing a research on fast locking PLL, and searching for its applications.
A fast locking PLL (frequency synthesizer) can truly provides a better data throughput in a system.
I've search through the internet and found that it's hard to find a specific application which needs a fast locking PLL.

Below is my questions about frequency hopping system and PLL:
1. Does a frequency hopping system requires a fast locking synthesizer?
2. Any specific specification? e.g. hopping distance is 500 MHz, locking time at least 1ms ...

 

[biff44]

most frequency hopping systems need a faster settling time than a PLL can do, so they use some sort of tunable DDS synthesizer that is upconverted with a fixed frequency PLL. However, slower systems can take advantage of it. Fast lock is just a way of opening up the bandwidth of the control loop filter temporarily during a change in integer number.

 

[BigBoss]

Locking Time depends on PLL Loop Filter specifications.If you design your filter wideband, the locking time will be shorter.Circuit speed of PLL IC is much quicker than other peripheral components.That's why looking for a high speed PLL IC doesn't make sense.Modern PLL circuits are pretty fast.In additional to, FastLock feature can be found on some PLL synthesizers that makes the first big capacitor short circuit for a while to accelerate the locking time.