Haptics audible noise reduction

A method comprising:

• composing a voltage waveform at a resonant frequency of a haptic actuator, wherein the voltage waveform comprises at least one half cycle divided into a drive portion, a ramp down portion, and a high impedance (high Z) portion, wherein during the drive portion, the voltage waveform is a wave at the resonant frequency, a voltage of the voltage waveform at an end of the drive portion being an end drive voltage, and wherein during the ramp down portion, the voltage of the voltage waveform changes from the end drive voltage to an end ramp down voltage, a magnitude of the end drive voltage (end drive voltage magnitude) being greater than a magnitude of the end ramp down voltage (end ramp down voltage magnitude), and a mag(dv/dt) at the end of the drive portion being less than the mag(dv/dt) at a beginning of the ramp down portion, the mag(dv/dt) representing a magnitude of change in the voltage of the voltage waveform over time;
• generating a control signal corresponding to the voltage waveform;
• and
• driving the haptic actuator with the voltage waveform using a haptic driver based on the control signal, wherein during the high Z portion, the haptic driver is disabled.

A device, comprising:

• means for composing a voltage waveform at a resonant frequency of a haptic actuator, wherein the voltage waveform comprises at least one half cycle divided into a drive portion, a ramp down portion, and a high impedance (high Z) portion, wherein during the drive portion, the voltage waveform is a wave at the resonant frequency, a voltage of the voltage waveform at an end of the drive portion being an end drive voltage, and wherein during the ramp down portion, the voltage of the voltage waveform changes from the end drive voltage to an end ramp down voltage, a magnitude of the end drive voltage (end drive voltage magnitude) being greater than a magnitude of the end ramp down voltage (end ramp down voltage magnitude), and a mag(dv/dt) at the end of the drive portion being less than the mag(dv/dt) at a beginning of the ramp down portion, the mag(dv/dt) representing a magnitude of change in the voltage of the voltage waveform over time;
• means for generating a control signal corresponding to the voltage waveform;
• and
• means for driving the haptic actuator with the voltage waveform based on the control signal, wherein during the high Z portion, the means for driving is disabled.

A non-transitory computer-readable medium storing computer-executable instructions for a device, the computer-executable instructions comprising:

• one or more instructions to instruct the device to compose a voltage waveform at a resonant frequency of a haptic actuator, wherein the voltage waveform comprises at least one half cycle divided into a drive portion, a ramp down portion, and a high impedance (high Z) portion, wherein during the drive portion, the voltage waveform is a wave at the resonant frequency, a voltage of the voltage waveform at an end of the drive portion being an end drive voltage, and wherein during the ramp down portion, the voltage of the voltage waveform changes from the end drive voltage to an end ramp down voltage, a magnitude of the end drive voltage (end drive voltage magnitude) being greater than a magnitude of the end ramp down voltage (end ramp down voltage magnitude), and a mag(dv/dt) at the end of the drive portion being less than the mag(dv/dt) at a beginning of the ramp down portion, the mag(dv/dt) representing a magnitude of change in the voltage of the voltage waveform over time;
• one or more instructions to instruct the device to generate a control signal corresponding to the voltage waveform;
• and
• one or more instructions to instruct the device to drive the haptic actuator with the voltage waveform using a haptic driver based on the control signal, wherein during the high Z portion, the haptic driver is disabled.