what applications does the ring oscillator have?

Hei, all friends:
I've seen that low phase CMOS ring oscillatior is so hot a topic these days. Is there anybody be so kind to tell me the applications of it? I really wonder if there are some products of it?

Thanks very much~

Hi, linlin

one ring oscillator is used in AM modulation (Ring modulation) , I don't know you mean it or not.

for more information you can see porakis or carlson's books.

I hope it'll be usefull

Ring oscillators are often used as part of a PLL for clock and data recovery, frequency synthesis and clock synchronization. Additionally, ring oscillators have both digital and analog features which make them useful for data conversion tasks such as phase and pulse width modulation.