NOISE SHAPING TIME TO DIGITAL CONVERTER
First Claim
1. A method of measuring a time difference between a signal of interest and a reference signal, comprising:
- operating a digitally controlled oscillator (DCO) at a first frequency during a first portion of the reference signal period;
changing the operating frequency of the DCO from the first frequency to a second frequency during the reference signal period as a function of the time difference between the signal of interest and the reference signal;
continuously counting how many signal transitions occur at an output of the DCO during the reference signal period; and
estimating the time difference between the signal of interest and the reference signal based on the number of signal transitions counted during the reference signal period.
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Accused Products
Abstract
According to an embodiment of a time to digital converter, the time difference between a signal of interest and a reference signal is measured by operating a digitally controlled oscillator at a first frequency during a first portion of the reference signal period and changing the operating frequency from the first frequency to a second frequency during the reference signal period as a function of the time difference between the signal of interest and the reference signal. The time to digital converter continuously counts how many signal transitions occur at an output of the digitally controlled oscillator during the reference signal period. The time difference between the signal of interest and the reference signal is estimated based on the number of signal transitions counted during the reference signal period.
5 Citations
20 Claims
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1. A method of measuring a time difference between a signal of interest and a reference signal, comprising:
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operating a digitally controlled oscillator (DCO) at a first frequency during a first portion of the reference signal period; changing the operating frequency of the DCO from the first frequency to a second frequency during the reference signal period as a function of the time difference between the signal of interest and the reference signal; continuously counting how many signal transitions occur at an output of the DCO during the reference signal period; and estimating the time difference between the signal of interest and the reference signal based on the number of signal transitions counted during the reference signal period. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A time to digital converter, comprising:
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a digitally controlled oscillator (DCO) configured to operate at a first frequency during a first portion of a period of a reference signal and change operating frequency from the first frequency to a second frequency during the reference signal period as a function of a time difference between a signal of interest and the reference signal; a counter circuit configured to continuously count how many signal transitions occur at an output of the DCO during the reference signal period; and an evaluation circuit configured to estimate the time difference between the signal of interest and the reference signal based on the number of signal transitions counted during the reference signal period. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification