Ring Oscillator for Providing Constant Oscillation Frequency
AssigneeInfineon Technologies AG
InventorsChin Yeong Koh, Kar Ming Yong
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Abstract
Some embodiments disclosed herein relate to techniques for providing a relatively constant oscillation frequency. In some instances, these techniques can make use of a ring oscillator that is powered by an adaptive voltage supply. The adaptive voltage supply provides a temperature-dependent supply voltage to respective delay elements in the ring oscillator, such that the oscillation frequency of the ring oscillator is approximately constant over a predetermined temperature range. For example, if temperature increases, the supply voltage can be increased proportionally, thereby tending to limit variation in the oscillation frequency delivered by the ring oscillator.
Claims19
A frequency generator, comprising:
- a ring oscillator comprising a number of delay elements coupled in series with one another, wherein an output of a last of the delay elements is coupled to an input of a first of the delay elements and provides an oscillating voltage having an oscillation frequency;
- an adaptive voltage supply configured to provide a supply voltage to respective delay elements of the ring oscillator;
- wherein the adaptive voltage supply is configured to vary the supply voltage over a temperature range to limit variations in the oscillation frequency over the temperature range.
A frequency generator, comprising:
- a ring oscillator comprising a number of delay elements coupled in series with one another, wherein an output of a last of the delay elements is coupled to an input of a first of the delay elements and provides an oscillating voltage having an oscillation frequency and a phase;
- an adaptive voltage supply configured to provide a supply voltage to respective delay elements of the ring oscillator;
- a phase comparator element configured to provide a tuning signal based on a difference, if any, between the phase of the oscillating voltage and a reference phase;
- wherein the adaptive voltage supply is configured to change the supply voltage in response to the tuning signal to limit variation in the oscillation frequency over a predetermined temperature range.
Dependencies are inferred from the claim text.