Abstract: An integrated current sensor includes a magnetic field transducer such as a Hall effect sensor, a magnetic core, and an electrical conductor. The conductor includes features for receiving portions of the Hall effect sensor and the core and the elements are dimensioned such that little or no relative movement among the elements is possible.

Abstract: An integrated sensor includes a magnetoresistance element electrically coupled to a device disposed on or integrated in a silicon substrate. A conductor is provided proximate to the magnetoresistance element. The integrated sensor can be used to provide various devices, such as a current sensor, a magnetic field sensor, or an isolator. Further, the integrated sensor can be used in an open loop configuration or in a closed loop configuration in which an additional conductor is provided. The magntoresistance element may be formed over the silicon substrate or on a separate, non-silicon substrate. Also described is an integrated sensor comprising a substrate, a magnetic field transducer disposed over a surface of the substrate, and a conductor disposed over the surface of the substrate proximate to the magnetic field transducer. The magnetic field transducer can be a Hall effect transducer or a magnetoresistance element.

Abstract: A proximity detector has a sequential flow state machine to identify states associated with a magnetic field signal provided by a magnetic field sensing element. The proximity detector can include a vibration processor to identify a vibration in response to the states.

Abstract: Apparatus for detecting failure of an isolation device includes a current sensor to sense current through the isolation device and a circuit responsive to the current sensor output signal and to an enable signal that controls the isolation device for providing an Early Failure Warning (EFW) signal indicative of whether the isolation device has failed. The enable signal is at a first logic level when the isolation device is on and is brought to a second logic level to disable and test the isolation device. Also described is a method of detecting a failure of an isolation device including disabling the isolation device, sensing a current through the isolation device, and providing an EFW signal indicating that the isolation device has failed if the current through the isolation device is greater than a predetermined level when the isolation device is disabled.

Abstract: A low power circuit for providing power and control signals to a low noise block converter of a satellite receiver over a single coaxial cable includes a tracking switch-mode power supply. The power and control signals have a DC voltage level selected from a plurality of DC voltage levels and are modulated by an analog AC tone signal. The switch-mode power supply provides a regulated output voltage which tracks the selected DC voltage level. The regulated output voltage provides the input voltage to an adjustable linear amplifier which generates an output voltage having the selected DC voltage level modulated by the analog AC tone signal.

Abstract: A proximity detector includes a fine DAC and a coarse DAC, outputs of which are summed to provide a tracking signal for tracking a magnetic field signal. The proximity detector provides two mode of operation. In a first mode of operation the coarse and fine DACs operate in combination as one higher order DAC. In a second mode of operation, the coarse DAC is provided with one or more extra counts, allowing the tracking signal to move more rapidly to track a rapidly changing magnetic field signal. In another embodiment, the proximity detector also includes an offset circuit for bringing at least one of the magnetic field signal and the tracking signal towards the other one of the magnetic field signal and the tracking signal.

Abstract: An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and substrate having a first surface in which is disposed one or more magnetic field transducers, with the first surface being proximate the current conductor portion and a second surface distal from the current conductor portion. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit relative to a conventional orientation. A current conductor portion can be deposited proximate to a surface of the substrate and proximate to the one or more magnetic field sensors.

Abstract: Apparatus and methods for detecting passing magnetic articles including an offset adjustment circuit for adjusting the DC level of the magnetic field signal based on a dynamically adjustable offset threshold signal. The detector includes a PDAC for tracking the positive peaks of a magnetic field signal and an NDAC for tracking the negative peaks of the magnetic field signal. In one embodiment, the offset threshold signal includes a positive offset threshold signal and a negative offset threshold signal that are initially set at fixed respective signal levels and that become the level of the PDAC signal and NDAC signals, respectively, in response to a counter, that counts a number of increments of the PDAC signal and decrements of the NDAC signal, reaching a predetermined count value.

Abstract: A switch which is magnetic pole insensitive is described. The switch includes a Hall effect sensor coupled to a threshold circuit which provides an output signal indicative of the proximity of a magnet, and hence a magnetic field, to the Hall effect sensor regardless of the orientation of the magnet to the Hall effect sensor.

Abstract: An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and a substrate having a first surface in which is disposed one or more magnetic field sensing elements, with the first surface being proximate to the current conductor portion and a second surface distal from the current conductor portion. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit in a flip-chap arrangement. The integrated circuit includes an overcurrent circuit responsive to a voltage drop generated by a current.

Abstract: A track-and-hold peak detector circuit, which can operate at low input signal frequencies, includes a capacitor to hold a peak voltage of the input signal and logic circuitry that reduces an effect of leakage current into or out of the capacitor, and therefore, provides protection against self-switching of an output signal of the peak detector circuit.

Abstract: Disclosed is a rotation detecting sensor suitable for use under a vibration-abundant condition as e.g. a sensor disposed in an automobile body for detecting rotation of an engine or ABS. The sensor includes a detecting element for detecting rotation of a rotary body as a change in a magnetic flux and outputting a signal and an integrated circuit for processing the amplified signal into a pulse corresponding to the detected rotation of the rotary body. The signal processing includes an initialization such as a gain adjustment for obtaining an appropriate gain for use in the subsequent process of conversion of the amplified signal to the pulse. According to this invention, a re-initialization is effected to obtain a new initial value such as a new gain if the previously effected initialization is determined inappropriate.

Abstract: Disclosed is a rotation detecting sensor suitable for use under a vibration-abundant condition as e.g. a sensor disposed in an automobile body for detecting rotation of an engine or ABS. The sensor includes a detecting element for detecting rotation of a rotary body as a change in a magnetic flux and outputting a signal and an integrated circuit for processing the amplified signal into a pulse corresponding to the detected rotation of the rotary body. The signal processing includes an initialization such as a gain adjustment for obtaining an appropriate gain for use in the subsequent process of conversion of the amplified signal to the pulse. According to this invention, a re-initialization is effected to obtain a new initial value such as a new gain if the previously effected initialization is determined inappropriate.

Abstract: A method and apparatus for providing information from a speed and direction sensor is disclosed. The method and apparatus detect the presence of a ferromagnetic object as it moves past a sensor. The sensor determines speed and direction information regarding the ferromagnetic object, and further provides information relating to the environment surrounding the sensor or object, such as the status of an air gap between the sensor and the moving object, and the temperature of the environment in which the sensor or object is disposed.

Abstract: An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and substrate having a first surface in which is disposed one or more magnetic field transducers, with the first surface being proximate the current conductor portion and a second surface distal from the current conductor portion. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit relative to a conventional orientation. A current conductor portion can be deposited on a surface of the substrate proximate to the one or more magnetic field sensors.

Abstract: A high pass filter comprising a combination of capacitors and insulated gate field effect transistors (IGFETs) used as effective resistors provides a low break frequency, while providing improved linearity and a stable break frequency over a relatively wide range of input voltages. The high pass filter can be realized with a small physical size. In one particular embodiment, the small physical size allows the capacitors and the IGFET devices to be integrated together onto a common substrate.

Abstract: A multi-mode switching regulator is capable of operating in a buck mode of operation, a boost mode of operation, and a buck-boost mode of operation. In the buck-boost mode of operation, the output voltage is regulated by adjusting a number of switch state transitions from a first state to a second state relative to a number of switch state transitions from the first state to a third state, and the duty cycle of each of the states is fixed from cycle to cycle in which the particular state occurs.

Abstract: A detector to determine the peak-to-peak value of a signal is presented. The detector includes a first circuit to provide a tracking signal that tracks a positive slope of the signal during a first time interval and a negative slope of the signal during a second time interval. The detector further includes a second circuit configured to produce values associated with the tracking signal provided during one of the first and second time intervals, where one of the values is indicative of the peak-to-peak value of the signal.

Abstract: A method and apparatus for providing information from a speed and direction sensor is disclosed. The method and apparatus detect the presence of a ferromagnetic object as it moves past a sensor. The sensor determines speed and direction information regarding the ferromagnetic object, and further provides information relating to the environment surrounding the sensor or object, such as the status of an air gap between the sensor and the moving object, and the temperature of the environment in which the sensor or object is disposed.

Abstract: An integrated current sensor includes a magnetic field transducer such as a Hall effect sensor, a magnetic core, and an electrical conductor. The conductor includes features for receiving portions of the Hall effect sensor and the core and the elements are dimensioned such that little or no relative movement among the elements is possible.