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US 8,138,808 B2Granted
Circuit for detecting phase imbalance of signals
AssigneeO2Micro, Inc.
InventorsYongbin Yuan, Jundong Zhu, Jingwei Zhang
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Abstract
A circuit for detecting a phase imbalance of signals includes a conversion block and a comparator coupled to the conversion block. The conversion block generates generating a direct current (DC) signal based on a first signal and a second signal. The level of the DC signal is determined by a phase difference between the first signal and the second signal. The comparator compares the DC signal to a reference signal and generates an alert signal if a difference between the DC signal and the reference signal is greater than a predetermined threshold.
Claims13
A circuit for detecting a phase imbalance, said circuit comprising:
- a buffer receiving an oscillation signal and generating a frequency signal, wherein a phase of a transfer function of said buffer is determined by a current flowing through said buffer;
- a first channel, coupled to said buffer, that receives an input signal, that shifts a frequency of said input signal according to said frequency signal to generate a first output signal, wherein a phase of said first output signal is determined by said phase of said transfer function of said buffer;
- a second channel receiving said input signal and generating a second output signal;
- a conversion block generating a direct current (DC) signal based on said first output signal and said second output signal, wherein a level of said DC signal is determined by a phase difference between said first output signal and said second output signal;
- a first comparator coupled to said conversion block, said first comparator comparing said DC signal to a first reference signal and generating a first alert signal if a difference between said DC signal and said first reference signal is greater than a first predetermined threshold;
- and
- a controller coupled to said first comparator, said controller receiving said first alert signal and adjusting said current through said buffer to adjust the phase of said first output signal in response to said first alert signal.
4 more elements
A method for detecting a phase imbalance, said method comprising:
- receiving an input signal;
- buffering an oscillation signal by a buffer to provide a frequency signal;
- shifting a frequency of said input signal according to said frequency signal to generate a first output signal;
- shifting a frequency of said input signal to generate a second output signal;
- generating a direct current (DC) signal indicative of a phase difference between said first output signal and said second output signal;
- comparing said DC signal to a reference signal;
- generating an alert signal if a difference between said DC signal and said reference signal is greater than a predetermined threshold;
- adjusting a current flowing through said buffer in response to said alert signal so as to adjust a phase of a transfer function of said buffer;
- and
- adjusting a phase of said first output signal according to said phase of said transfer function of said buffer.
7 more elements
A signal transfer system, comprising:
- a pair of buffers buffering an oscillation signal generated by an oscillator to provide a first frequency signal and a second frequency signal;
- a first channel receiving an input signal and shifting a frequency of said input signal according to said first frequency signal to generate a first output signal;
- a second channel receiving said input signal and shifting a frequency of said input signal according to said second frequency signal to generate a second output signal, wherein a phase difference between said first channel and said second channel is determined by a current flowing through said buffers;
- a detection circuit coupled to said first and said second channels, said direction circuit generating a direct current (DC) signal indicating a phase difference between said first signal and said second signal, and generating an alert signal by comparing a difference between said DC signal and a reference signal with a predetermined threshold;
- and
- a controller coupled to said detection circuit, said controller adjusting said current flowing through said buffers based on said alert signal to adjust said phase difference.
3 more elements
Dependencies are inferred from the claim text.