Magnetic sensor circuits and systems and methods for forming magnetic sensor circuits
First Claim
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1. A sensor circuit, comprising:
- a first magnetoresistor having a first resistance transfer function, the first magnetoresistor comprising a first magnetic free layer configured to spontaneously generate a first vortex magnetization pattern in the first magnetic free layer, and a first magnetic reference layer having a first straight reference magnetization pattern;
a second magnetoresistor having a second, different, resistance transfer function, the second magnetoresistor comprising a second magnetic free layer configured to spontaneously generate a second vortex magnetization pattern in the second magnetic free layer, and a second magnetic reference layer having a second straight reference magnetization pattern,wherein the first magnetoresistor and the second magnetoresistor are connected, by a common node, in series between a first supply terminal and a second supply terminal of the sensor circuit, andwherein an annihilation field strength for removing the first vortex magnetization pattern in the first magnetic free layer of the first magnetoresistor is different from an annihilation field strength for removing the second vortex magnetization pattern in the second magnetic free layer of the second magnetoresistor; and
a monitoring circuit configured to monitor a monitored voltage as a voltage difference between the common node and a reference node and configured to generate a warning signal based on the monitored voltage and a reference voltage, wherein the warning signal indicates that at least one of the first magnetoresistor and the second magnetoresistor is in saturation,wherein the monitoring circuit is configured to generate the warning signal when the monitored voltage deviates by more than a predefined threshold amount from the reference voltage and maintain the warning signal until a signal turn-off condition is satisfied,wherein, while the warning signal is not being generated by the monitoring circuit, the monitoring circuit is configured to continue to not generate the warning signal when the monitored voltage does not deviate by more than the predefined threshold amount from the reference voltage,wherein, while the warning signal is being generated by the monitoring circuit, the monitoring circuit is configured to cease generating the warning signal only when the signal turn-off condition is satisfied,wherein the monitoring circuit is configured to monitor for a discontinuous voltage jump in the monitored voltage and determine that the signal turn-off condition is satisfied only when the discontinuous voltage jump is detected,wherein the discontinuous voltage jump is a discontinuous change in the monitored voltage from a saturation voltage value to being equal to the reference voltage without the monitored voltage being equal to any intermediate voltage between the saturation voltage value and the reference voltage,wherein the saturation voltage value is a voltage value generated as the monitored voltage when at least one of the first magnetoresistor and the second magnetoresistor is in saturation and differs from the reference voltage by an amount greater than the predefined threshold amount,wherein, while the warning signal is being generated by the monitoring circuit, the monitoring circuit is configured to maintain the warning signal despite the monitored voltage not deviating by more than the predefined threshold amount from the reference voltage if the discontinuous voltage jump is not detected by the monitoring circuit, andwherein the reference voltage is 0V.
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Abstract
A sensor circuit includes a first magnetoresistor. The first magnetoresistor has a first resistance transfer function. Furthermore, the sensor circuit includes a second magnetoresistor. The second magnetoresistor has a second resistance transfer function. The second resistance transfer function is different from the first resistance transfer function. The first magnetoresistor and the second magnetoresistor are connected in series between a first supply terminal of the sensor circuit and a second supply terminal of the sensor circuit.
15 Citations
27 Claims
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1. A sensor circuit, comprising:
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a first magnetoresistor having a first resistance transfer function, the first magnetoresistor comprising a first magnetic free layer configured to spontaneously generate a first vortex magnetization pattern in the first magnetic free layer, and a first magnetic reference layer having a first straight reference magnetization pattern; a second magnetoresistor having a second, different, resistance transfer function, the second magnetoresistor comprising a second magnetic free layer configured to spontaneously generate a second vortex magnetization pattern in the second magnetic free layer, and a second magnetic reference layer having a second straight reference magnetization pattern, wherein the first magnetoresistor and the second magnetoresistor are connected, by a common node, in series between a first supply terminal and a second supply terminal of the sensor circuit, and wherein an annihilation field strength for removing the first vortex magnetization pattern in the first magnetic free layer of the first magnetoresistor is different from an annihilation field strength for removing the second vortex magnetization pattern in the second magnetic free layer of the second magnetoresistor; and a monitoring circuit configured to monitor a monitored voltage as a voltage difference between the common node and a reference node and configured to generate a warning signal based on the monitored voltage and a reference voltage, wherein the warning signal indicates that at least one of the first magnetoresistor and the second magnetoresistor is in saturation, wherein the monitoring circuit is configured to generate the warning signal when the monitored voltage deviates by more than a predefined threshold amount from the reference voltage and maintain the warning signal until a signal turn-off condition is satisfied, wherein, while the warning signal is not being generated by the monitoring circuit, the monitoring circuit is configured to continue to not generate the warning signal when the monitored voltage does not deviate by more than the predefined threshold amount from the reference voltage, wherein, while the warning signal is being generated by the monitoring circuit, the monitoring circuit is configured to cease generating the warning signal only when the signal turn-off condition is satisfied, wherein the monitoring circuit is configured to monitor for a discontinuous voltage jump in the monitored voltage and determine that the signal turn-off condition is satisfied only when the discontinuous voltage jump is detected, wherein the discontinuous voltage jump is a discontinuous change in the monitored voltage from a saturation voltage value to being equal to the reference voltage without the monitored voltage being equal to any intermediate voltage between the saturation voltage value and the reference voltage, wherein the saturation voltage value is a voltage value generated as the monitored voltage when at least one of the first magnetoresistor and the second magnetoresistor is in saturation and differs from the reference voltage by an amount greater than the predefined threshold amount, wherein, while the warning signal is being generated by the monitoring circuit, the monitoring circuit is configured to maintain the warning signal despite the monitored voltage not deviating by more than the predefined threshold amount from the reference voltage if the discontinuous voltage jump is not detected by the monitoring circuit, and wherein the reference voltage is 0V. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A magnetic sensor bridge circuit, comprising:
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a first magnetoresistive vortex sensor element and a second magnetoresistive vortex sensor element connected in series; a third magnetoresistive vortex sensor element and a fourth magnetoresistive vortex sensor element connected in series, wherein the first magnetoresistive vortex sensor element and the third magnetoresistive vortex sensor element are connected to a first supply terminal of the magnetic sensor bridge circuit, wherein the second magnetoresistive vortex sensor element and the fourth magnetoresistive vortex sensor element are connected to a second, different, supply terminal of the magnetic sensor bridge circuit, wherein the first magnetoresistive vortex sensor element and the fourth magnetoresistive vortex sensor element have a first resistance transfer function with a first annihilation field strength for removing a vortex magnetization pattern in a magnetic free layer of the first magnetoresistive vortex sensor element and removing a vortex magnetization pattern in a magnetic free layer of the fourth magnetoresistive vortex sensor element, and wherein the second magnetoresistive vortex sensor element and the third magnetoresistive vortex sensor element have a second resistance transfer function with a second annihilation field strength for removing a vortex magnetization pattern in a magnetic free layer of the second magnetoresistive vortex sensor element and removing a vortex magnetization pattern in a magnetic free layer of the third magnetoresistive vortex sensor element, wherein the first resistance transfer function and the second resistance transfer function are different from each other, and the first annihilation field strength and the second annihilation field strength are different from each other; and a monitoring circuit configured to monitor a voltage between a first common terminal of the first magnetoresistive vortex sensor element and the second magnetoresistive vortex sensor element and a second common terminal of the third magnetoresistive vortex sensor element and the fourth magnetoresistive vortex sensor element, and configured to generate a warning signal based on the monitored voltage and a reference voltage, wherein the warning signal indicates that at least one of the first, the second, the third, and the fourth magnetoresistive vortex sensor element is in saturation, wherein the monitoring circuit is configured to generate the warning signal when the monitored voltage deviates by more than a predefined threshold amount from the reference voltage and maintain the warning signal until a signal turn-off condition is satisfied, wherein, while the warning signal is not being generated by the monitoring circuit, the monitoring circuit is configured to continue to not generate the warning signal when the monitored voltage does not deviate by more than the predefined threshold amount from the reference voltage, wherein, while the warning signal is being generated by the monitoring circuit, the monitoring circuit is configured to cease generating the warning signal only when the signal turn-off condition is satisfied, wherein the monitoring circuit is configured to monitor for a discontinuous voltage jump in the monitored voltage and determine that the signal turn-off condition is satisfied only when the discontinuous voltage jump is detected, wherein the discontinuous voltage jump is a discontinuous change in the monitored voltage from a saturation voltage value to being equal to the reference voltage without the monitored voltage being equal to any intermediate voltage between the saturation voltage value and the reference voltage, wherein the saturation voltage value is a voltage value generated as the monitored voltage when at least one of the first magnetoresistor and the second magnetoresistor is in saturation and differs from the reference voltage by an amount greater than the predefined threshold amount, wherein, while the warning signal is being generated by the monitoring circuit, the monitoring circuit is configured to maintain the warning signal despite the monitored voltage not deviating by more than the predefined threshold amount from the reference voltage if the discontinuous voltage jump is not detected by the monitoring circuit, and wherein the reference voltage is 0V. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A sensor system, comprising:
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a first magnetic sensor bridge circuit comprising a first magnetoresistive vortex sensor element and a second magnetoresistive vortex sensor element connected in series and a third magnetoresistive vortex sensor element and a fourth magnetoresistive vortex sensor element connected in series, wherein the first magnetoresistive vortex sensor element and the third magnetoresistive vortex sensor element are connected to a first supply terminal of the sensor system, wherein the second magnetoresistive vortex sensor element and the fourth magnetoresistive vortex sensor element are connected to a second, different, supply terminal of the sensor system, and wherein the first magnetoresistive vortex sensor element and the fourth magnetoresistive vortex sensor element have a first resistance transfer function with a first annihilation field strength for removing a vortex magnetization pattern in a magnetic free layer of the first magnetoresistive vortex sensor element and removing a vortex magnetization pattern in a magnetic free layer of the fourth magnetoresistive vortex sensor element; a second magnetic sensor bridge circuit located in proximity to the first magnetic sensor bridge circuit and comprising a fifth magnetoresistive vortex sensor element and a sixth magnetoresistive vortex sensor element connected in series and a seventh magnetoresistive vortex sensor element and an eighth magnetoresistive vortex sensor element connected in series, wherein the fifth magnetoresistive vortex sensor element and the seventh magnetoresistive vortex sensor element are connected to a third supply terminal of the sensor system, wherein the sixth magnetoresistive vortex sensor element and the eighth magnetoresistive vortex sensor element are connected to a fourth, different, supply terminal of the sensor system, and wherein the fifth magnetoresistive vortex sensor element and the eighth magnetoresistive vortex sensor element have a second resistance transfer function with a second annihilation field strength for removing a vortex magnetization pattern in a magnetic free layer of the fifth magnetoresistive vortex sensor element and removing a vortex magnetization pattern in a magnetic free layer of the eighth magnetoresistive vortex sensor element, wherein the first resistance transfer function and the second resistance transfer function are different from each other, and the first annihilation field strength and the second annihilation field strength are different from each other; and a monitoring circuit configured to monitor a voltage between a first test terminal and a second test terminal of the sensor system, and configured to generate a warning signal based on the monitored voltage and a reference voltage, wherein the warning signal indicates that at least one of the first, the second, the third, the fourth, the fifth, the sixth, the seventh, and the eight magnetoresistive vortex sensor element is in saturation, wherein the monitoring circuit is configured to generate the warning signal when the monitored voltage deviates by more than a predefined threshold amount from the reference voltage and maintain the warning signal until a signal turn-off condition is satisfied, wherein, while the warning signal is not being generated by the monitoring circuit, the monitoring circuit is configured to continue to not generate the warning signal when the monitored voltage does not deviate by more than the predefined threshold amount from the reference voltage, wherein, while the warning signal is being generated by the monitoring circuit, the monitoring circuit is configured to cease generating the warning signal only when the signal turn-off condition is satisfied, wherein the monitoring circuit is configured to monitor for a discontinuous voltage jump in the monitored voltage and determine that the signal turn-off condition is satisfied only when the discontinuous voltage jump is detected, wherein the discontinuous voltage jump is a discontinuous change in the monitored voltage from a saturation voltage value to being equal to the reference voltage without the monitored voltage being equal to any intermediate voltage between the saturation voltage value and the reference voltage, wherein the saturation voltage value is a voltage value generated as the monitored voltage when at least one of the first magnetoresistor and the second magnetoresistor is in saturation and differs from the reference voltage by an amount greater than the predefined threshold amount, wherein, while the warning signal is being generated by the monitoring circuit, the monitoring circuit is configured to maintain the warning signal despite the monitored voltage not deviating by more than the predefined threshold amount from the reference voltage if the discontinuous voltage jump is not detected by the monitoring circuit, and wherein the reference voltage is 0V. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27)
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Specification