Patent ID: 7498887
Filing Date: 2009-03-03
Classification: G06F,H03K

Abstract:
1. A high frequency digital oscillator synchronized to a low frequency oscillator signal s in having a frequency f in and gated by the rising edge of signal s in , the oscillator comprising: a) a ring oscillator having an odd number of digital gates and an adjustable feedback loop, the ring oscillator having a signal s i) a starting ring oscillator frequency approximately equal to a multiple 2 ii) an ability to fine adjust its frequency f iii) an output whose rising edge of signal s iv) control signal means to trigger the ring oscillator with every rising edge of s v) control signal means to sustain oscillations of the ring oscillator for a minimum of a single period signal of s vi) means for maintaining the ring oscillator output s b) a multiplicity of signals s c) means for selecting the one signal s d) means for measuring the integral number k of periods p e) means of determining the delta Δ=p f) means for using the resulting delta Δ to adjust the frequency of f