Advanced Micro Devices, Inc.
ADAPTIVE DCO VF CURVE SLOPE CONTROL

Abstract:

An oscillator circuit is provided that adapts to voltage supply variations. The circuit first and second delays lines connected inputs of an edge detector, one delay line supplied by a reference voltage and the other with a drooping supply voltage. The edge detector generates an output clock based on a relationship between the inputs. The output clock applied to the signal inputs of the first and second delay lines. The output clock has a voltage dependent frequency performance curve with a slope dependent at least on the second delay line delay and a delay of the edge detector. At least one of the first delay line, the second delay line, and the edge detector delay are adjusted to change the slope of the performance curve.