Oscillators – Automatic frequency stabilization using a phase or frequency... – Afc with logic elements
Patent
1994-06-07
1995-11-28
Pascal, Robert J.
Oscillators
Automatic frequency stabilization using a phase or frequency...
Afc with logic elements
331 57, H03L 700
Patent
active
054711762
ABSTRACT:
A clock generation circuit includes a reference clock for putting out a stable reference clocking signal. A digital ring oscillator includes a series circuit loop having at least one inverting gate and a programmable delay line of plural delays formed a series of tapped digital transmission gates connected between an output and an input of the inverting gate. A multiplexer selects among the series of taps in accordance with a tap selection signal. A clock monitoring circuit is connected to compare the clock output with a stable reference clocking signal to produce a digital clock cycle count. A programmed microcontroller generates the tap selection value as a function of the digital clock cycle count and a desired clock output frequency set point. And, a synchronization circuit synchronizes tap selection value applied to the multiplexer in relation to the present, adjustable clocking signal, and to a logical state of a successor, adjustable clocking signal to be put out by the digital ring oscillator following the tap selection, in order to avoid glitches and without interrupting oscillation.
REFERENCES:
patent: 4517532 (1985-05-01), Neidorff
patent: 4884041 (1989-11-01), Walker
patent: 4998075 (1991-03-01), Patton, III et al.
patent: 5048811 (1991-09-01), Lewis
patent: 5061907 (1991-10-01), Rasmussen
patent: 5087842 (1992-02-01), Pulsipher et al.
patent: 5122761 (1992-06-01), Wischermann
patent: 5126692 (1992-06-01), Shearer et al.
patent: 5136260 (1992-08-01), Yousefi-Elezei
patent: 5191301 (1993-03-01), Mullgrav, Jr.
patent: 5208557 (1993-05-01), Kersh, III
patent: 5233316 (1993-08-01), Yamada et al.
patent: 5241429 (1993-08-01), Holsinger
patent: 5255136 (1993-10-01), Machado et al.
Akin, Jr. William R.
Henson James A.
Richmond Scott E.
Harrison David B.
Pascal Robert J.
Quantum Corporation
Vu David H.
LandOfFree
Glitchless frequency-adjustable ring oscillator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Glitchless frequency-adjustable ring oscillator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Glitchless frequency-adjustable ring oscillator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2016064