Qualcomm Incorporated

Massachusetts Institute of Technology

Nathaniel Jay T Salazar

Joseph Dale Rutkowski

Liangguo Shen

Shivaprakash Halagur

David J Perreault

Wei Li

Joshua Zazzera

In an aspect, an actuator driver includes a first digital adder configured to output an adjusted control signal based on combining an input control signal and a filtered difference signal, a digital pulse width modulation (PWM) generator configured to convert the adjusted control signal to one or more PWM signals, and an H-bridge amplifier configured to output one or more driving signals based on the one or more PWM signals. The actuator driver further includes a feedback signal generator configured to generate a feedback signal based on the one or more driving signals, a second digital adder configured to output a difference signal based on subtracting the feedback signal from the adjusted control signal, and a loop filter configured to generate the filtered difference signal based on the difference signal.

Actuator driver

Innovative techniques to design and generate haptics waveforms are proposed. The proposed techniques reduce or eliminate audible noises being generated by a haptic actuator during operation. A haptic controller may compose a voltage waveform at a resonant frequency of the haptic actuator and generate a corresponding control signal. Instead of suddenly entering a high impedance state from a driving state, the voltage waveform may include a ramp down portion in which the voltage ramps down continuously but quickly so that the current flowing within the actuator is brought down before entering the high impedance state. In this way, audible noises may be reduced or even eliminated.

Haptics audible noise reduction

A voltage-step down rectifier topology suitable for integration on a die of an integrated circuit is described. In one embodiment, a switched capacitor rectifier is provided having an architecture such that an input voltage swing of the switched-capacitor rectifier is a factor N times an output voltage where N depends upon the number of stages such that the switched-capacitor rectifier can provide a &#x3c0;/(2N) step-down voltage conversion ratio between an input fundamental ac peak voltage to the output dc voltage. In one embodiment, the rectifier is used in dc-dc conversion. In one embodiment, the rectifier is used in ac power delivery to low-voltage electronics.

Apparatus for multi-level switched-capacitor rectification and DC-DC conversion

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San Diego, CA, United States of America

Nathaniel Jay T Salazar