Abstract: A demodulation signal generator, coupled to an air-pulse generator comprising a flap pair, includes a resonance circuit. The resonance circuit produces a first demodulation signal and a second demodulation signal. The resonance circuit and the flap pair co-perform a resonance operation, such that the first demodulation signal and the second demodulation signal are generated via the co-performed resonance operation and have opposite polarity. The flap pair performs a differential movement to form an opening to perform a demodulation operation on a modulated air pressure variation.

Abstract: An air-pulse generating device includes a film structure including a flap pair. The film structure is actuated to perform a common mode movement, so as to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is actuated to perform a differential mode movement, so as to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation.

Abstract: The present invention discloses a feedback control system. The feedback control system comprises a plant, configured to produce an output according to a control signal; a first summing block, configured to produce a first difference between an input signal and a measured output signal; a first controller, configured to generate the control signal, such that the first difference decreases to be less than a first threshold or is less than the first threshold; wherein the first controller comprises a memory configured to store a table, and the table contains information of a plurality of transfer functions corresponding to a plurality of operating conditions; wherein the first controller determines an operating condition under which the plant operates, and chooses to utilize a transfer function corresponding to the operating condition to generate the control signal according to the transfer function and the first difference.

Abstract: A package structure includes a first substrate and a first device disposed on the first substrate. The first device includes at least one anchor structure, a film structure anchored by the anchor structure and an actuator configured to control the film structure to form a first vent temporarily. The film structure partitions a space into a first volume to be connected to an ear canal and a second volume connected to an ambient of a wearable sound device. The ear canal and the ambient are connected via the first vent when the first vent is opened. The first vent is opened by controlling a first membrane portion and a second membrane portion of the film structure, such that a difference between a first displacement of the first membrane portion and a second displacement of the second membrane portion is larger than a thickness of the film structure.

Abstract: A method is applied in a controller within a driving circuit comprising a driving sub-circuit configured to drive a load. The method comprises steps of: performing a table learning operation on a table at least at a first rate during a learning period; and performing the table learning operation on the table at a second rate lower than the first rate after the learning period; wherein the table is stored in a memory within the controller. The table learning operation comprises steps of: receiving a first feedback signal from the load corresponding to a first cycle; obtaining a control code from the table according to the first feedback signal; generating a control signal according to the control code; receiving a second feedback signal from the load corresponding to the second cycle; and updating the control code and saving the updated control code back to the table in the memory.

Abstract: A method is applied in a controller within a driving circuit comprising a driving sub-circuit configured to drive a load. The method comprises steps of: performing a table learning operation on a table at least at a first rate during a learning period; and performing the table learning operation on the table at a second rate lower than the first rate after the learning period; wherein the table is stored in a memory within the controller. The table learning operation comprises steps of: receiving a first feedback signal from the load corresponding to a first cycle; obtaining a control code from the table according to the first feedback signal; generating a control signal according to the control code; receiving a second feedback signal from the load corresponding to the second cycle; and updating the control code and saving the updated control code back to the table in the memory.

Abstract: A method, which is applied in a driving circuit including an analog-to-digital convertor (ADC) and a switching circuit including an inductor and coupled to a load, includes steps of: performing an analog-to-digital conversion on a load voltage of the load at a first rate; and producing at least a current pulse flowing through the inductor at a second rate. Wherein, each current pulse among the at least a current pulse is accomplished within a second cycle corresponding to the second rate, all of the at least a current pulse are accomplished within a first cycle corresponding to the first rate, and a first length of the first cycle is longer than twice of a second length of the second cycle.

Abstract: An air-pulse generating device includes a film structure. The film structure is driven by a modulation-driving signal, so as to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is driven by a first demodulation-driving signal and a second demodulation-driving signal, so as to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation.

Abstract: A feedback control system configured to drive a load is disclosed. The feedback control system includes an up-sampling circuit, configured to perform an un-sampling operation on a source signal and produce an up-sampled signal with an up-sampling frequency according to the up-sampled signal and a feedback signal from the load; a delta circuit, coupled to the up-sampling circuit and configured to produce a delta signal; a sigma circuit, configured to produce a density modulation signal according to the delta signal; and a driving device, configured to drive the load according to the density modulation signal with the up-sampling frequency.

Abstract: An air-pulse generating device includes a film structure. The film structure is actuated such that the air-pulse generating device produces a plurality of air pulses. A horn-shaped outlet is formed within the air-pulse generating device, and the plurality of air pulses is propagated via the horn-shaped outlet.

Abstract: An air-pulse generating device includes a film structure including a flap pair. The film structure is actuated to perform a common mode movement, so as to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is actuated to perform a differential mode movement, so as to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation.

Abstract: The present invention discloses a feedback control system. The feedback control system comprises a plant, configured to produce an output according to a control signal; a first summing block, configured to produce a first difference between an input signal and a measured output signal; a first controller, configured to generate the control signal, such that the first difference decreases to be less than a first threshold or is less than the first threshold; wherein the first controller comprises a memory configured to store a table, and the table contains information of a plurality of transfer functions corresponding to a plurality of operating conditions; wherein the first controller determines an operating condition under which the plant operates, and chooses to utilize a transfer function corresponding to the operating condition to generate the control signal according to the transfer function and the first difference.

Abstract: A method is applied in a pulse width modulation (PWM) controller within a driving circuit including a bidirectional circuit coupled to a load. The method includes steps of: obtaining a pulse width control code (PWCC) from a table stored in a memory within the PWM controller according to a difference between a first feedback signal from the load and an input signal, wherein the PWCC is corresponding to an intended voltage difference, and the first feedback signal is corresponding to a first cycle; generating a plurality of PWM signals according to the PWCC, wherein during a second cycle the bidirectional circuit performs a charging or discharging operation on the load according to the PWM signals; receiving a second feedback signal from the load corresponding to the second cycle; and updating the PWCC according to the first and second feedback signals, and saving the updated PWCC back to the table.

Abstract: An air-pulse generating device includes a film structure. The film structure is driven to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is driven to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation, and the plurality of air pulses is asymmetric.

Abstract: A method is applied in a pulse width modulation (PWM) controller within a driving circuit including a bidirectional circuit coupled to a load. The method includes steps of: obtaining a pulse width control code (PWCC) from a table stored in a memory within the PWM controller according to a difference between a first feedback signal from the load and an input signal, wherein the PWCC is corresponding to an intended voltage difference, and the first feedback signal is corresponding to a first cycle; generating a plurality of PWM signals according to the PWCC, wherein during a second cycle the bidirectional circuit performs a charging or discharging operation on the load according to the PWM signals; receiving a second feedback signal from the load corresponding to the second cycle; and updating the PWCC according to the first and second feedback signals, and saving the updated PWCC back to the table.

Abstract: An air-pulse generating device includes a membrane structure, a valve structure, and a cover structure. A chamber is formed between the membrane structure, the valve structure and the cover structure. An air wave vibrating at an operating frequency is formed within the chamber. The valve structure is configured to be actuated to perform an open-and-close movement to form at least one opening. The at least one opening connects air inside the chamber with air outside the chamber. The open-and-close movement is synchronous with the operating frequency.

Abstract: An air-pulse generating device includes a membrane structure, a valve structure, and a cover structure. A chamber is formed between the membrane structure, the valve structure and the cover structure. An air wave vibrating at an operating frequency is formed within the chamber. The valve structure is configured to be actuated to perform an open-and-close movement to form at least one opening. The at least one opening connects air inside the chamber with air outside the chamber. The open-and-close movement is synchronous with the operating frequency.

Abstract: A successive approximation register (SAR) analog-to-digital converter (ADC) includes a comparator, a threshold generator and a controller. The comparator receives an analog signal and the SAR ADC outputs an output codeword. The comparator performs a plurality of first comparisons and a plurality of second comparisons. The controller determines a plurality of most significant bits of the output codeword according to a plurality of first comparison results corresponding to the first comparisons. The first comparisons are performed by comparing the analog signal with a plurality of first thresholds. The controller determines a plurality of least significant bits of the output codeword according to a plurality of second comparison results corresponding to the second comparisons. The second comparisons are performed by comparing the analog signal with a second threshold.

Abstract: A venting device is disposed within a wearable sound device or to be disposed within the wearable sound device. The venting device includes an anchor structure, a film structure and an actuator. The film structure includes an anchor end anchored on the anchor structure and a free end, and the film structure is configured to form a vent or close the vent. The actuator is disposed on the film structure. The film structure partitions a space into a first volume and a second volume, and the first volume and the second volume are connected via the vent when the vent is formed. The venting device is controlled by the controller to seal the vent when the controller determines to close the vent.

Abstract: A method, which is applied in a driving circuit including an analog-to-digital convertor (ADC) and a switching circuit including an inductor and coupled to a load, includes steps of: performing an analog-to-digital conversion on a load voltage of the load at a first rate; and producing at least a current pulse flowing through the inductor at a second rate. Wherein, each current pulse among the at least a current pulse is accomplished within a second cycle corresponding to the second rate, all of the at least a current pulse are accomplished within a first cycle corresponding to the first rate, and a first length of the first cycle is longer than twice of a second length of the second cycle.