Fairchild Semiconductor Corporation

Semiconductor Components Industries, LLC

Philip Crawley

Majid Shushtarian

William David Llewellyn

Earl Schreyer

In one embodiment, a power supply control circuit may include a capacitive boost circuit having only three switches and only one boost capacitor. The capacitive boost circuit may be configured to receive an input voltage and form a first voltage to apply to an inductor. A control circuit of the power supply control circuit may be configured to switch an inductor switch at a first frequency to regulate the output voltage to the desired value, to switch the three switches at substantially the same frequency, and to adjust a duty cycle of the three switches.

Method of forming a power supply control circuit and structure therefor

Generally, this disclosure provides circuitry and methods for determining the output capacitance of an output load capacitor of a power supply. The output capacitance is generally determined by beginning a calibration period and charging an output capacitor with a current source to generate an output voltage. The output voltage may be compared to a reference voltage, and a time period is determined during which the output voltage is less than the reference voltage. The capacitance value, C, of the output capacitor may be determined based on, at least in part, the determined time period. This disclosure also provides circuitry and methods to adjust certain parameters of the power supply based on the determined C value. For example, in a ramp compensation portion of the power supply, the value of a ramp capacitor and/or reset resistor may be adjusted once the value of C is determined. This may enable, for example, increased efficiency, greater stability and increased bandwidth operation of the power supply when the output load capacitor is changed for different applications.

Load capacitance determination circuitry and power supply control

In a general aspect, a battery pack can include a battery configured to supply power to a connected device and to receive re-charge power from a charger circuit. The battery pack can further include a current modulating circuit configured to modulate current of the battery between first and second supply terminals of the battery pack. The battery pack can also include a controller configured to provide voltage protection of the battery pack and charge current control of the battery using the current modulating circuit. The controller can be configured, while the battery is being charged, to compare, at the battery pack, a charge voltage setpoint of the battery pack with a desired charging voltage; modify, at the battery pack, the charge voltage setpoint to achieve the desired charging voltage; and provide the modified charge voltage setpoint from the battery pack to a connected device.

Control and current measurement function for battery charging, protection and fuel gauge coulomb counting

In one general aspect, a method can include calculating, at a calibration temperature of a speaker, a calibration parameter through a coil of the speaker in response to a first test signal, and can include sending a second test signal through the coil of the speaker. The method can also include measuring a parameter through the coil of the speaker based on the second test signal, and calculating a temperature change of the coil of the speaker based on the parameter and based on the calibration parameter at the calibration temperature.

Methods and apparatus related to protection of a speaker

Protection of a speaker using temperature calibration

This document discusses, among other things, apparatus and methods for controlling a haptic transducer. In an example, a haptic controller can include an active termination driver having a configurable output impedance. The active termination driver can be configured to drive a haptic transducer and to process back electro-magnetic force (EMF) of the haptic transducer to provide motion feedback of the haptic transducer. In an example, the haptic controller can include a processor to provide a command signal to the active termination driver and to determine a resonant frequency of the haptic device using the motion feedback of the haptic transducer.

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Oceanside, CA, United States of America

Philip Crawley