Abstract: In an embodiment, a magnetic field sensor comprises a substrate and a first magnetoresistive element supported by the substrate. The magnetic field sensor also includes a second magnetoresistive element supported by the substrate and coupled in series with the first magnetoresistive element to form a voltage node between the first and second magnetoresistive elements, and at which an output voltage is provided that changes in response to an external magnetic field. The magnetic field sensor also includes a magnetic source that produces a local magnetic field having a strength sufficient to bias the first magnetoresistive element to a resistive value that is substantially resistant to changing in response to the external magnetic field. In embodiments, additional magnetoresistive elements are included to form an H-bridge circuit.

Abstract: In one aspect, a silicon-controller rectifier (SCR) includes a first N+ region; a first P+ region; a second N+ region; a second P+ region; and a P+/Intrinsic/N+ (PIN) diode disposed between the first P+ region and the second N+ region. The PIN diode includes a third N+ region, a third P+ region and an intrinsic material disposed between the third N+ region and the third P+ region. An anode terminal of the SCR connects to the first N+ region and the first P+ region and a cathode terminal of the SCR connects to the second N+ region and the second P+ region. A first distance between the third N+ region and the third P+ region controls the trigger voltage of the SCR and a second distance corresponding to a length of each of the third P+ region and the third N+ region controls the holding voltage of the SCR.

Abstract: Electronic circuits provide an error signal to control a regulated output voltage signal generated by a controllable DC-DC converter for driving one or more series connected strings of light emitting diodes.

Abstract: In one aspect, a vertical Hall effect sensor includes a semiconductor wafer having a first conductivity type and a plurality of semiconductive electrodes disposed on the semiconductor wafer. The plurality of semiconductive electrodes have the first conductivity type and include a source electrode, a first sensing electrode and a second sensing electrode, arranged such that the source electrode is between the first sensing electrode and the sensing electrode and a first drain electrode and a second drain electrode, arranged such that the first sensing electrode, second sensing electrode, and source electrode are between the first drain electrode and the second drain electrode. The vertical Hall effect sensor also includes a plurality of semiconductor fingers disposed on the semiconductor wafer and interdigitated with the plurality of semiconductive electrodes, the semiconductor fingers having a second conductivity type.

Abstract: A system includes a magnetic target and a magnetic field sensor. The magnetic field sensor comprises an output node; a circuit to detect a magnetic field produced by the magnetic target; and a processor. The processor may be configured to transmit a signal onto the output node representing the detected magnetic field; detect whether the transmitted signal is interrupted by an external source; and, if the signal is interrupted, initiate a self-test of the apparatus. Corresponding methods and apparatuses are also disclosed.

Abstract: Methods and apparatus to provide an integrated circuit package having a conductive leadframe, a non-conductive die paddle mechanically coupled to the leadframe, and a die disposed on the die paddle and electrically connected to the leadframe. With this arrangement, eddy currents are reduced near the magnetic field transducer to reduce interference with magnetic fields.

Abstract: A motor driver includes at least two terminals suitable for being coupled to a motor controller and to receive a motor command signal and transmit a motor status signal when the motor driver is controlling a motor. A serial data communication circuit may be configured to send and receive serial data over the at least two terminals when the at least two terminals are idle.

Abstract: A system for controlling a motor may include a motor driver circuit for driving a camera motor. A memory capable of storing a plurality of parameters for controlling the camera motor may also be included. A set of parameters from the memory may be chosen to be applied to driving the motor. A motor control module may receive a signal from the control logic module, apply the chosen set of parameters to driving the camera motor, and command the motor driver circuit to drive the motor in accordance with the applied set of parameters. The parameters may be chosen based on desired behavior of the system and various other stimuli.

Abstract: A magnetic field sensor has internal power supply generating circuits to generate a higher operating voltage for a magnetic field sensing element, resulting in a magnetic field sensor with improved sensitivity to magnetic fields.

Abstract: A transistor drive circuit uses multi-stage slew rate control to drive one or more switching transistors. After a decision is made to change transistor state, a first drive current may be applied to an input terminal of the transistor for a predetermined time duration. After the predetermined time duration, a second drive current may be applied to the input terminal. When the transition between states is substantially complete, the current drive to the input terminal may be changed to a voltage drive. In some embodiments, the predetermined time duration may be based on the start time of a Miller plateau during the transition period.

Abstract: Circuits and methods provide an ability to track a direction of a magnetic field, and, more particular, to track a direction of a rapidly rotating magnetic field. The circuits and methods use a plurality of magnetic field sensing elements, for example, as may be embodied in a circular vertical Hall (CVH) sensing element. However, the circuits and methods can track the direction of the sensed magnetic field by processing at any time fewer than all of the plurality of magnetic field sensing elements, for example, one or two of the plurality of magnetic field sensing elements.

Abstract: A regulator control circuit includes a switch control signal generator to generate a switch control signal and a soft start circuit to generate a soft start signal for use by the switch control signal generator. The soft start circuit includes a soft start controller and a decreasing circuit to decrease the soft start signal in response to the soft start controller. The soft start controller may comprise a non-regulation detector to detect a non-regulation condition. Embodiments include decreasing the soft start signal in response to a non-regulation condition lasting a predetermined time, detecting the non-regulation condition in response to a maximum duty cycle of the regulator switch, generating a soft start level indicator to control decreasing the soft start signal, and maintaining the soft start signal at a predetermined relationship with respect to a feedback signal.

Abstract: A motor control circuit and associated techniques can drive an electric motor in a start-up mode of operation followed by a normal mode of operation. The motor control circuit and techniques can receive a selection signal provided by a user that can select one of a plurality of sets of parameter values that determine characteristics of drive signals applied to the motor during the start-up mode of operation. The motor control circuit and associated techniques can synchronize operation between the start-up mode of operation and the normal mode of operation.

Abstract: Methods and apparatus for a circuit including a DC-DC converter including: a boost converter to provide a DC voltage output from a DC input voltage, the DC output voltage configured to connect with a first load terminal, a feedback module configured to connect with a second load terminal, a switching module having a switching element coupled to the boost converter, and a control circuit coupled to the switching module to control operation of the switching element, the control circuit coupled to the feedback module, wherein the control circuit includes a slope generator to generate a ramp signal having a slope that can vary cycle to cycle.

Abstract: A driver circuit for driving a switch includes a high output impedance driver circuit portion having a high impedance output node coupled to the control terminal of the transistor and a low output impedance driver circuit portion having a low impedance output node also coupled to the control terminal of the transistor. The slew rate of the control signal is established by at least one of the high impedance driver circuit portion and the low impedance driver circuit portion.

Abstract: Circuits and methods used therein provide an adjustable average current through a load in accordance with a pulse width modulated (PWM) signal. A condition detection circuit is configured to identify a condition of the electronic circuit and to generate a condition signal indicative of the condition. A current extension circuit is coupled receive the condition signal and coupled to receive the PWM signal. The current extension circuit is configured to generate, at the output node of the current extension circuit, an extended PWM signal having a first state and a second state. The first state of the extended PWM signal longer in time than a first state of the PWM signal by an amount related to a value or a state of the condition signal. Current pulses through the load are extended to be longer in accordance with the extended PWM signal.

Abstract: Systems, methods, and apparatuses for magnetic field sensors with self-test include a detection circuit to detect speed and direction of a target. One or more circuits to test accuracy of the detected speed and direction may be included. One or more circuits to test accuracy of an oscillator may also be included. One or more circuits to test the accuracy of an analog-to-digital converter may also be included. Additionally, one or more IDDQ and/or built-in-self test (BIST) circuits may be included.

Abstract: 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.

Abstract: Methods and apparatus for a magnetic field sensor in a molded IC package having a magnetic field sensing element in a die with a component coupled to a leadframe at a downset area. In embodiments, a thickness of the leadframe in the downset area is less than a thickness of the leadframe in a non-downset area adjacent to the downset area.

Abstract: A magnetic field sensor, a magnetic assembly, and a method provide circuits and techniques for or measuring one or more displacement angles of a magnet using magnetic field sensing elements. Applications include, but are not limited to, joysticks.