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.
I am not sure if it is relevant to your application but a PLL kick circuit is sometimes used in some servo systems to force swing through the capture range to achieve initial lock when the system has a very narrow operating capture and lock range.
One example is with the optical servo in a CD/DVD player where at switch-on the focus servo is kicked and forced to sweep through a large range to achieve initial focus lock.
You confirmed by message that it is for a DVD read circuit.
There are various kick signals (they are normally applied while the servo is switched to open loop). One method for the focus search is in the form of a critically damped sinusoidal. This could be generated by a RLC circuit exited with a pulse. The moment focus is achieved (FOK), the loop is electronically closed again. This is sometimes called the focus search signal.
The other is a fixed current pulse applied to the tracking coil with the tracking servo in open loop during the pulse period. This is normally used for relatively short track jumps, such as for cue/review operations.
I am only speculating on this. To generate the fixed pulse should be no problem. To generate the damped sinusoid you will need some kind of digital waveform generation where the shape is read out of memory and produced with a DAC. This is not my area of expertise, so maybe other members can help you on this side.
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.
