Abstract: A system for measuring current includes a conductive trace comprising N substantially parallel straight sections having a substantially constant cross-section, N?4. Adjacent substantially straight sections are spaced apart by a given distance and each pair of adjacent straight sections is connected by a respective loop of the current trace such that current in odd-numbered straight sections flows in a first direction and current in even-numbered straight sections flows in an opposite direction. The N magnetic field based current sensors are each positioned on a respective straight section of the conductive trace.

Abstract: A closed-loop calibration scheme is configured to allow a device to remain in continuous operation. A signal generator device provides a pseudorandom sequence for a signal received by a magnetic field magnetic field sensor, such as a Hall-effect sensor. A signal decoder circuit receives the output signal and decouples the generated spread spectrum signal from the interference by measuring the gain in the overall signal. The decoder device distinguishes the known spread spectrum signal from any perturbation effects of particular bandwidths. A processing circuit then outputs a signal that has an operation parameter that has been adjusted to compensate for the perturbation effects. The processing circuit provides the receiver circuit with the compensation signal, hence forming a closed-loop calibration configuration.

Abstract: A closed-loop calibration scheme is configured to allow a device to remain in continuous operation. A signal generator device provides a pseudorandom sequence for a signal received by a magnetic field magnetic field sensor, such as a Hall-effect sensor. A signal decoder circuit receives the output signal and decouples the generated spread spectrum signal from the interference by measuring the gain in the overall signal. The decoder device distinguishes the known spread spectrum signal from any perturbation effects of particular bandwidths. A processing circuit then outputs a signal that has an operation parameter that has been adjusted to compensate for the perturbation effects. The processing circuit provides the receiver circuit with the compensation signal, hence forming a closed-loop calibration configuration.

Abstract: A system for measuring current includes a conductive trace comprising N substantially parallel straight sections having a substantially constant cross-section, N?4. Adjacent substantially straight sections are spaced apart by a given distance and each pair of adjacent straight sections is connected by a respective loop of the current trace such that current in odd-numbered straight sections flows in a first direction and current in even-numbered straight sections flows in an opposite direction. The N magnetic field based current sensors are each positioned on a respective straight section of the conductive trace.

Abstract: A method and apparatus for a hand-held device for ensuring a secured mode transition. The method includes receiving a request to transition to a mode, determining the mode of the hand-held device, transitioning to a transition mode relevant to the received request, wherein the relevant transition mode ensures that the transition is securely executed, setting the device in accordance with the received request, and transitioning to the mode requested.

Abstract: A method for operating a handheld calculator having a controllable power domain is provided. The method includes receiving, by the handheld calculator, a signal to power down the handheld calculator, storing context information of at least one component in the controllable domain in an external memory, setting a boot indicator to indicate a quick boot on power up, and removing power from the controllable power domain.

Abstract: A directional controller for a device is provided. The directional controller consists of keypad contacts, a keyboard, and a button. The keypad contacts are on a printed circuit board. The keyboard has more than four keys and each key is disposed adjacent to one of the keypad contacts. The button is operable for pivoting engagement with the more than four keys to promote contact between the more than four keys and the adjacent one of the keypad contacts.

Abstract: A method and apparatus for a hand-held device for ensuring a secured mode transition. The method includes receiving a request to transition to a mode, determining the mode of the hand-held device, transitioning to a transition mode relevant to the received request, wherein the relevant transition mode ensures that the transition is securely executed, setting the device in accordance with the received request, and transitioning to the mode requested.

Abstract: A method and apparatus relating to a hand-held device. The hand-held device comprising a visual indicator utilized to indicate at least one a normal mode or a press-to-test mode, and where in the setting of the visual indicator are tamper proof.

Abstract: A power interruption protection module, system and method. The power interruption protection module, comprising a charging module for storing a boosted display voltage, a detecting module for identifying at least one of a drop or an increase of a functioning system voltage, wherein at least one of the drop or the increase is beyond a threshold, and a regulating module for receiving a signal from the detecting module, wherein the signal determines at least one of the drop or the increase beyond the threshold, and wherein the regulating module allows or stops the flow of the stored boosted display voltage of the charging module according to the signal of the detecting module.

Abstract: A directional controller for a device is provided. The directional controller consists of keypad contacts, a keyboard, and a button. The keypad contacts are on a printed circuit board. The keyboard has more than four keys and each key is disposed adjacent to one of the keypad contacts. The button is operable for pivoting engagement with the more than four keys to promote contact between the more than four keys and the adjacent one of the keypad contacts.