Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
VCO can have a control voltage and still be un-locked. Steering a VCO with a voltage from say a variable bench PSU does not make it locked. I would say free-running is anything outside the closed PLL loop. A loop can be opened and the control voltage can go either pin high or low, depending on the design.
Wording from a patent document
BACKGROUND OF THE INVENTION
Electronic devices such as RF (Radio Frequency) receivers, transmitters and various other devices include a VCO operating within a PLL (Phase Locked Loop) to maintain a desired oscillation frequency.
It is conventional practice to tune a VCO to a particular initial frequency before it leaves its factory. This is typically accomplished by using factory equipment to measure the frequency of the VCO while it is free-running (i.e., the PLL is opened),
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
