Allegro Microsystems, LLC

Michael G Ward

David Jamie Haas

Weihua Chen

William P Taylor

Alexander Latham

Virag V Chaware

Method and apparatus for a magnetic sensor device having a magnetic field sensing element to generate an output signal and a signal processing module coupled to the magnetic field sensing element, the signal processing module including a linearization module to apply a third order Taylor expansion term to the output signal generated by the magnetic field sensing element. An output module can receive the linearized signal from the linearization module and provide a device output signal.

Magnetic sensor having enhanced linearization

In one aspect, a current driver, includes an operational amplifier that includes a first input port configured to receive a reference signal and a second input port configured to receive a variable signal. The variable signal is a function of an output current of the current driver. The reference signal corresponds to a selected maximum output current of the current driver. The current driver also includes a feedback transistor comprising a gate coupled to the output of the operational amplifier and a summing junction coupled to a drain of the feedback transistor and configured to receive a signal from the drain to enable clamping of the output current of the current driver to the maximum output current when the variable signal exceeds the reference signal. The summing junction is coupled to a set of transistors configured to provide the output current of the current driver.

Current driver with output current clamping

A control loop circuit for use in a closed-loop control system that controls a system such as a linear motor is presented. The control loop circuit includes a lead-lag compensator that features a lead compensation network configured to reduce output noise without substantially changing the effect of the lead compensation in the control system's frequency response.

Closed-loop motor driver compensation

A magnetic field sensor includes a compensation loop coupled in series with normal circuit couplings in order to reduce a transient signal that would otherwise be generated when the magnetic field sensor experiences a high rate of change of magnetic field. In some embodiments, the magnetic field sensor is a current sensor responsive to a magnetic field generated by a current-carrying conductor.

Apparatus and method for reducing a transient signal in a magnetic field sensor

A mechanism for assigning unique addresses to identical devices attached to a serial bus is presented. Each device has at least one output and is provided with a storage device to provide a configurable portion of a bus address having a fixed portion and a configurable portion. The device is further provided with circuitry, coupled to the storage device and the output, to determine a state of the output and use the state to configure the configurable portion. Once the configurable portion is configured, the bus address uniquely identifies the device. Such configuration allows more than one such device to be coupled to the same serial bus, e.g., an IC bus.

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Wells, ME, United States of America

Michael G Ward