[PLL] What is free running clock

[maulin sheth]

Hello all,

Can anyone guide me,What is the Free Running Clock?
What is the use of Free Running Clock?

Thanks in Advance.

 

[rca]

Free running clock means the pll does not try to lock on a reference clock.

 

[maulin sheth]

Free running clock means the pll does not try to lock on a reference clock.

Pl Can anyone help me for the depth understanding???

 

[rca]

Well google and Wikipedia is your friend, that is the based of the pll behavior you need to learn.
A pll try to follow a reference clock, and act on a VCO voltage control oscillator to follow this clock. Some dividers and multiplier are in the different paths to increased or decreased the clock frequency.

 

[sun_ray]

A free running clock is just a clock from which other clock can also be derived.

 

[atulaxc]

Free running clock is not part of any standard. This is just a way of showing the independence in phase relationship of a clock on a chip to other clocks. The PLL's on chip can used free running clocks as input to generate fixed output clocks. This link has details on PLL.