# US 12,222,384 B2 · Circuits and methods for detecting line short circuits and/or line interruptions in differentially operated line networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,222,384 B2 - Document ID: US12222384B2 - Status: Granted - Kind: B2 - Application number: 17/452,284 - Filed: 2021-10-26 - Published: 2022-05-05 - Granted: 2025-02-11 - Earliest claimed: 2020-10-30 - Assignees: Infineon Technologies AG - Applicants: Infineon Technologies AG - Inventors: Mario Motz; Florian Brugger; Carlos Humberto Garcia Rojas; Francesco Polo; Tobias Werth - Web page: https://patentgrep.com/patent/US12222384B2 ## CPC - G01D 5/2046: {by a movable ferromagnetic element, e.g. a core} - G01R 31/2829: {Testing of circuits in sensor or actuator systems (testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844)} - G01D 3/08: with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown - G01D 5/20: by varying inductance, e.g. by a movable armature - G01D 5/2073: {by movement of a single coil with respect to two or more coils} - G01R 31/006: {on road vehicles, e.g. automobiles or trucks (testing of ignition installations peculiar to internal combustion engines F02P17/00)} - H02H 1/0007: {concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445)} - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) ## Abstract The present disclosure relates to circuits for detecting a line short circuit and/or a line interruption in a differentially operated line network, comprising at least one control circuit configured to control at least one common-mode signal of the differentially operated line network vis-à-vis a predefined common-mode signal variable and to indicate a line short circuit and/or a line interruption in the differentially operated line network if at least one control or controlled variable of the control circuit exceeds a predefined threshold value. ## Claims ### Claim 1 A circuit for detecting a line short circuit and/or a line interruption in a differentially operated line network, comprising: at least one control circuit configured to: control at least one common-mode signal of the differentially operated line network vis-à-vis a predefined common-mode signal variable, and indicate at least one of a line short circuit in the differentially operated line network or a line interruption in the differentially operated line network when at least one control or controlled variable exceeds a predefined threshold value. ### Claim 2 (depends on 1) The circuit as claimed in claim 1, wherein the at least one control circuit is configured as an analog control circuit. ### Claim 3 (depends on 1) The circuit as claimed in claim 1, wherein the at least one control circuit has a transconductance amplifier having at least one feedback output for a control current, wherein the at least one feedback output is configured to feed the control current back to one or more of a common-mode signal source of the differentially operated line network or a signal line of the differentially operated line network. ### Claim 4 (depends on 3) The circuit as claimed in claim 3, wherein the transconductance amplifier has a plurality of feedback outputs for a plurality of signal lines of the differentially operated line network. ### Claim 5 (depends on 3) The circuit as claimed in claim 3, wherein the transconductance amplifier has one feedback output for the common-mode signal source. ### Claim 6 (depends on 3) The circuit as claimed in claim 3, wherein the at least one control circuit has a current comparison circuit configured to: compare the control current provided via the at least one feedback output of the transconductance amplifier with at least one predefined threshold current provided via at least one current source, and indicate at least one of a line short circuit or a line interruption in the differentially operated line network when the control current exceeds the predefined threshold current in terms of absolute value. ### Claim 7 (depends on 3) The circuit as claimed in claim 3, wherein the at least one control circuit has a detection circuit configured to: ascertain whether one or more transistors of at least one current source of the transconductance amplifier for providing the control current via the at least one feedback output leaves a saturation region, and indicate at least one of a line short circuit or a line interruption in the differentially operated line network when the saturation region is left. ### Claim 8 (depends on 1) The circuit as claimed in claim 1, wherein the at least one control circuit is configured as a digital control circuit. ### Claim 9 (depends on 8) The circuit as claimed in claim 8, wherein the at least one control circuit comprises: an analog-to-digital converter (ADC), an input of the ADC being coupled to a differentially operated line pair of the differentially operated line network; a digital signal processing circuit configured to: compare common-mode signals of the differentially operated line pair that have been subjected to analog-to-digital conversion using the ADC with a common-mode signal setpoint variable, and determine a digital control signal based on comparing the common-mode signals of the differentially operated line pair that have been subjected to the analog-to-digital conversion using the ADC with the common-mode signal setpoint variable; and a feedback path for the digital control signal with a digital-to-analog converter (DAC), for controlling a common-mode signal source of the differentially operated line pair. ### Claim 10 (depends on 1) The circuit as claimed in claim 1, furthermore comprising: at least one injection current source configured to inject, in addition to the at least one common-mode signal, at least one direct current (DC) current or at least one alternating current (AC) current into the differentially operated line network without affecting differential signal routing. ### Claim 11 (depends on 10) The circuit as claimed in claim 10, wherein the at least one injection current source is configured as switchable, in order to be applied alternately to different signal lines of the differentially operated line network. ### Claim 12 (depends on 1) The circuit as claimed in claim 1, wherein the differentially operated line network comprises a differentially operated inductor capacitor (LC) exciter resonant circuit of an inductive angle sensor. ### Claim 13 (depends on 1) The circuit as claimed in claim 1, wherein the differentially operated line network comprises a plurality of differentially operated sensor coils of an inductive angle sensor. ### Claim 14 An inductive angle sensor, comprising: an inductor capacitor (LC) exciter resonant circuit, wherein the LC exciter resonant circuit is differentially operated using an integrated oscillator circuit; and a control circuit configured to: control a common-mode signal for the LC exciter resonant circuit vis-à-vis a predefined common-mode signal variable, and indicate at least one of a line short circuit or a line interruption in the LC exciter resonant circuit when at least one control or controlled variable exceeds a predefined threshold value. ### Claim 15 (depends on 14) The inductive angle sensor as claimed in claim 14, wherein the control circuit has a transconductance amplifier coupled to the differentially operated LC exciter resonant circuit on an input side and having at least one feedback output for a control current which is fed back to at least one of the integrated oscillator circuit or at least one signal line of the differentially operated LC exciter resonant circuit. ### Claim 16 (depends on 15) The inductive angle sensor as claimed in claim 15, wherein the transconductance amplifier has a feedback output for each signal conductor of a signal line pair of the differentially operated LC exciter resonant circuit, or wherein the transconductance amplifier has exactly one feedback output for the integrated oscillator circuit. ### Claim 17 (depends on 14) The inductive angle sensor as claimed in claim 14, wherein the control circuit comprises: an analog-to-digital converter (ADC), wherein an input of the ADC is coupled to a line pair of the differentially operated LC exciter resonant circuit; a digital signal processing circuit configured to compare common-mode signals of the line pair that have been subjected to analog-to-digital conversion using the ADC with a common-mode signal setpoint variable and to determine a digital control signal based on comparing the common-mode signals of the line pair that have been subjected to the analog-to-digital conversion using the ADC with the common-mode signal setpoint variable; and a feedback path for the digital control signal with a digital-to-analog converter (DAC) for converting the digital control signal into an analog control current for the integrated oscillator circuit. ### Claim 18 (depends on 14) The inductive angle sensor as claimed in claim 14, furthermore comprising for each signal conductor of a signal line pair of the differentially operated LC exciter resonant circuit, a direct current (DC) current source configured to inject, in addition to the common-mode signal, a DC current into a respective signal conductor, without affecting differential signal routing in the differentially operated LC exciter resonant circuit. ### Claim 19 An inductive angle sensor, comprising: a plurality of differentially operated sensor coils arranged in a phase-offset manner; and a control circuit configured to control at least one common-mode signal of the plurality of differentially operated sensor coils vis-à-vis a predefined common-mode signal variable and to indicate at least one of a line short circuit or a line interruption for the plurality of differentially operated sensor coils when at least one control or controlled variable exceeds a predefined threshold value. ### Claim 20 (depends on 19) The inductive angle sensor as claimed in claim 19, furthermore comprising: for each of the plurality of differentially operated sensor coils, a direct current (DC) current source configured to inject, in addition to the respective common-mode signal, a DC current into a respective signal line, without affecting differential signal routing in the plurality of differentially operated sensor coils. ### Claim 21 (depends on 20) The inductive angle sensor as claimed in claim 20, wherein each of the DC current sources is switchable alternately to different sensor coils from among the differentially operated sensor coils. ### Claim 22 (depends on 20) The inductive angle sensor as claimed in claim 20, wherein the control circuit has a transconductance amplifier coupled to the plurality of differentially operated sensor coils on an input side and having at least one feedback output for a control current which is fed back to at least one signal line of the plurality of differentially operated sensor coils. ### Claim 23 (depends on 22) The inductive angle sensor as claimed in claim 22, wherein the feedback output is switchable alternately to different sensor coils from among the plurality of differentially operated sensor coils. ### Claim 24 (depends on 19) The inductive angle sensor as claimed in claim 19, furthermore comprising: an evaluation circuit, wherein the evaluation circuit is coupled to the plurality of differentially operated sensor coils arranged in a phase-offset manner and is configured to determine a rotation angle of an inductive rotor arrangement based on induction signals of the plurality of differentially operated sensor coils. ### Claim 25 (depends on 24) The inductive angle sensor as claimed in claim 24, wherein the evaluation circuit is furthermore configured to indicate, based on at least one common-mode signal of the plurality of differentially operated sensor coils arranged in the phase-offset manner, at least one of a line short circuit or a line interruption for the plurality of differentially operated sensor coils when at least one of the at least one common-mode signal leaves a predefined tolerance range. ### Claim 26 An inductive angle sensor comprising: at least one differentially operated coil; an injection current source configured to inject a direct current (DC) current into the at least one differentially operated coil; and a registering circuit configured to determine a voltage drop across terminals of the at least one differentially operated coil that is caused by the DC current, wherein at least one of: the injection current source is configured to inject the DC current into the at least one differentially operated coil without the injected DC current affecting differential signal routing, the registering circuit is configured to output a fault signal when the voltage drop across the terminals of the at least one differentially operated coil exceeds a predefined threshold value, or the registering circuit has a low-pass filter configured to suppress alternating current (AC) signals. ### Claim 27 (depends on 26) The inductive angle sensor as claimed in claim 26, wherein the injection current source is configured to inject the DC current into the at least one differentially operated coil without the injected DC current affecting differential signal routing. ### Claim 28 (depends on 26) The inductive angle sensor as claimed in claim 26, wherein the registering circuit is configured to output the fault signal when the voltage drop across the terminals of the at least one differentially operated coil exceeds the predefined threshold value. ### Claim 29 (depends on 26) The inductive angle sensor as claimed in claim 26, wherein the registering circuit has the low-pass filter configured to suppress the AC signals. ### Claim 30 (depends on 26) The inductive angle sensor as claimed in claim 26, comprising: a demodulator circuit arranged between the terminals of the at least one differentially operated coil and the registering circuit and configured, in a first operating mode for angle measurement, during a first switching phase, to switch a first terminal of the at least one differentially operated coil to a first input of the registering circuit and a second terminal of the at least one differentially operated coil to a second input of the registering circuit and, during a second switching phase, to switch the first terminal of the at least one differentially operated coil to the second input of the registering circuit and the second terminal of the at least one differentially operated coil to the first input of the registering circuit and, in a second operating mode for determining the voltage drop across the terminals of the at least one differentially operated coil, to switch the first terminal of the coil permanently to the first input of the registering circuit and the second terminal of the at least one differentially operated coil permanently to the second input of the registering circuit. ### Claim 31 (depends on 26) The inductive angle sensor as claimed in claim 26, furthermore comprising: a control circuit configured to control at least one common-mode signal of the at least one differentially operated coil vis-à-vis a predefined common-mode signal variable and to indicate at least one of a line short circuit or a line interruption for the at least one differentially operated coil when at least one control or controlled variable exceeds a predefined threshold value.