Circuit and method of signal detection
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorWei Chih Chen
Life of this patent
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Abstract
A circuit includes an input stage, a comparison stage, and a calibration stage. The input stage is configured to receive a first input signal, to generate a first reference signal, and to generate a second reference signal. The comparison stage is configured to generate a first comparison output signal in response to the first reference signal and a third reference signal and to generate a second comparison output signal in response to the second reference signal and a fourth reference signal. The calibration stage is configured to generate a detection signal responsive to the presence of the first comparison output signal and the second comparison output signal having a signal frequency within a predetermined frequency band.
Claims21
A circuit, comprising:
- an input stage having a first input node, a first output node, and a second output node, the input stage being configured to:
- generate a first reference signal at the first output node of the input stage;
- and
- generate a second reference signal at the second output node of the input stage;
- a comparison stage having a first input node, a second input node, a first output node, and a second output node, the first input node of the comparison stage being coupled to the first output node of the input stage, and the second input node of the comparison stage being coupled to the second output node of the input stage, the comparison stage being configured to:
- generate a first comparison output signal at the first output node of the comparison stage in response to the first reference signal and a third reference signal;
- and
- generate a second comparison output signal at the second output node of the comparison stage in response to the second reference signal and a fourth reference signal;
- and
- a calibration stage coupled to the comparison stage and configured to generate a detection signal responsive to the presence of
- the first comparison output signal being an alternating current (AC) signal having a signal frequency within a predetermined frequency band;
- and
- the second comparison output signal being an AC signal having a signal frequency within the predetermined frequency band.
A circuit, comprising:
- a first source follower circuit having an input node and an output node;
- a first resistor having a first end and a second end, the first end of the first resistor coupled to the output node of the first source follower circuit;
- a first comparator having a negative input node, a positive input node, and an output node, the positive input node of the first comparator being coupled to the first end of the first resistor;
- a second comparator having a negative input node, a positive input node, and an output node, the negative input node of the second comparator being coupled to the second end of first the resistor;
- and
- a calibration stage having a first input node, a second input node, and an output node, the first input node coupled to the output node of the first comparator, the second input node coupled to the output node of the second comparator, and the calibration stage being configured to generate a detection signal at the output terminal of the calibration stage responsive to the presence of
- a first comparison output signal at the output node of the first comparator has a signal frequency within a predetermined frequency band;
- and
- a second comparison output signal at the output node of the second comparator has a signal frequency within the predetermined frequency band.
A method of detecting if an input signal has a signal swing greater than a first predetermined voltage level and a signal frequency within a predetermined frequency band, the method comprising:
- generating a first reference signal at a first node of an input stage;
- generating a second reference signal at a second node of the input stage;
- generating a first comparison output signal in response to the first reference signal and a third reference signal;
- generating a second comparison output signal in response to the second reference signal and a fourth reference signal;
- and
- generating, by a calibration stage configured to receive the first and second comparison output signals, a detection signal responsive to presence of:
- the first comparison output signal having a signal frequency within the predetermined frequency band;
- and
- the second comparison output signal having a signal frequency within the predetermined frequency band.
Dependencies are inferred from the claim text.