Abstract: A wheel speed sensor interface receives an analog signal from a wheel speed sensor and converts the analog signal to a digital wheel speed sensor output signal. A detector circuit is configured to detect a transient occurring within a voltage source powering the wheel speed sensor, and compensate the digital wheel speed sensor output signal as a function of the detection of the transient so that it is an accurate representation of a wheel speed detected by the wheel speed sensor. The detector circuit includes a current mirror coupled to the voltage source, and outputs a compensation current to a current comparator of the wheel speed sensor interface.

Abstract: A method and apparatus for resistive short circuit immunity for wheel speed sensor interface on braking system. In one embodiment the apparatus includes a first circuit for transmitting a first current to a wheel speed sensor, and a second circuit for receiving a second current from the wheel speed sensor. Another circuit is coupled to the first and second circuits and configured to detect and respond to a near zero resistive short between the wheel speed sensor and ground. In this embodiment the circuit is configured to detect the near zero resistive short based on a direct or indirect comparison between magnitudes of the first and second currents to a first predetermined value, and based on a direct or indirect comparison between magnitudes of the first and second currents to a second predetermined value.

Abstract: A method and apparatus for resistive short circuit immunity for wheel speed sensor interface on braking system. In one embodiment the apparatus includes a first circuit for transmitting a first current to a wheel speed sensor, and a second circuit for receiving a second current from the wheel speed sensor. Another circuit is coupled to the first and second circuits and configured to detect and respond to a near zero resistive short between the wheel speed sensor and ground. In this embodiment the circuit is configured to detect the near zero resistive short based on a direct or indirect comparison between magnitudes of the first and second currents to a first predetermined value, and based on a direct or indirect comparison between magnitudes of the first and second currents to a second predetermined value.

Abstract: A wheel speed sensor interface receives an analog signal from a wheel speed sensor and converts the analog signal to a digital wheel speed sensor output signal. A detector circuit is configured to detect a transient occurring within a voltage source powering the wheel speed sensor, and compensate the digital wheel speed sensor output signal as a function of the detection of the transient so that it is an accurate representation of a wheel speed detected by the wheel speed sensor. The detector circuit includes a current mirror coupled to the voltage source, and outputs a compensation current to a current comparator of the wheel speed sensor interface.

Abstract: An apparatus and method for resistive short circuit immunity for wheel speed sensor interface on a braking system. In one embodiment the apparatus includes a first circuit for generating a first periodic signal based on first current transmitted to a wheel speed sensor and a second circuit for generating a second periodic signal based on second current, some or all of which is received from the wheel speed sensor. A circuit is provided for selecting the first periodic signal for output if a magnitude of the second current is greater than a magnitude of the first current, or the second periodic signal for output if a magnitude of the second current is not greater than the magnitude of the first current. The selected first or second periodic signal contains information relating to a speed of a wheel that is associated with the wheel speed sensor.

Abstract: A sensor circuit, including at least a first sensor arranged to selectively receive a first test current; a first digital-to-analog converter, DAC, arranged to receive a first signal from the first sensor and output a first compensation signal in response thereto; a second DAC arranged to receive a second signal from a second sensor and output a second compensation signal in response thereto; and a controller operably coupled to the first and second DACs and operable to determine from at least one of: the first compensation signal and second compensation signal whether a short condition exists between the first sensor and the second sensor.

Abstract: A sensor circuit includes at least one signal processing circuit connectable to at least one sensor operable on a channel and configured to receive and process a periodic sensor signal therefrom the sensor circuit further includes a switching device coupled between the signal processing circuit and the at least one sensor, at least one switch coupled to the switching device and a controller connected to the at least one switch and to an output of the signal processing circuit. The controller is operable to re-configure the switching device via control of the switch and determine whether a short condition exists on the at least one sensor or channel based on the output from the signal processing circuit.

Abstract: A current sense circuit for a PWM driver comprises: a PWM control circuit comprising: a first switching device arranged to receive a PWM signal from the PWM driver whose current is to be sensed; and a second switching device whose supply current is arranged to track the sensed current of the PWM driver. An ADC is operably coupled to the first and second switching device. The ADC comprises: a DAC arranged to provide a current sense to the second switching device that tracks the current passing through the PWM driver; a first comparator arranged to receive and compare an output current from the DAC and an output current from the first switching device; and a first successive approximation register arranged to receive an output from the comparator and provide: a first output to the ADC; and a second output that provides a representation of the sensed current.

Abstract: A sensor circuit, comprising at least: a first sensor arranged to selectively receive a first test current; a first digital-to-analog converter, DAC, arranged to receive a first signal from the first sensor and output a first compensation signal in response thereto; a second DAC arranged to receive a second signal from a second sensor and output a second compensation signal in response thereto; and a controller operably coupled to the first and second DACs and operable to determine from at least one of: the first compensation signal and second compensation signal whether a short condition exists between the first sensor and the second sensor.

Abstract: A sensor circuit, comprising: at least one signal processing circuit connectable to at least one sensor operable on a channel and configured to receive and process a periodic sensor signal therefrom; a switching device coupled between the signal processing circuit and the at least one sensor, at least one switch coupled to the switching device; and a controller connected to the at least one switch and an output of the signal processing circuit. The controller is operable to re-configure the switching device via control of the switch and determine whether a short condition exists on the at least one sensor or channel based on the output from the signal processing circuit.

Abstract: A current sense circuit for a PWM driver comprises: a PWM control circuit comprising: a first switching device arranged to receive a PWM signal from the PWM driver whose current is to be sensed; and a second switching device whose supply current is arranged to track the sensed current of the PWM driver. An ADC is operably coupled to the first and second switching device. The ADC comprises: a DAC arranged to provide a current sense to the second switching device that tracks the current passing through the PWM driver; a first comparator arranged to receive and compare an output current from the DAC and an output current from the first switching device; and a first successive approximation register arranged to receive an output from the comparator and provide: a first output to the ADC; and a second output that provides a representation of the sensed current.