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.
svensl,
A VCO is a free-running oscilator whose output frequency is controlled by a DC voltage. As such, phase has no meaning, because there is no reference with which to compare the phase. However, in its most common application, a phase locked loop, the VCO integrates the phase difference between the reference input and the output. If you draw a diagram of two square waves that have 90 degrees phase shift between them, you will see that this is the condition under which the
difference waveform is perfectly symmetrical, and, therefore has a zero integral (long term). It is this integral that is used to adjust the frequency of the local oscillator in the VCO. As a result, if the VCO is under equilibrium conditions, its output will be shifted 90 degrees with respect to the reference.
regards,
Kral
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.
