Xmems Labs, Inc.

Jing-Meng Liu

Jemm Yue Liang

Hsi-Sheng Chen

Chiung C Lo

Wen-Chien Chen

Jye Ren

Chieh-Yao Chang

Hung-Chi Huang

Shun-Nan Tai

A period determination circuit for determining conduction period for energy-recycling circuit includes an indication circuit, coupled to an inductor of the energy-recycling circuit to receive an inductor voltage, configured to generate an indication signal according to the inductor voltage, wherein the indication signal reflects a status corresponding to a first conduction period of the energy-recycling circuit; and a control signal generator, coupled to a switch of the energy-recycling circuit, configured to generate a control signal with a second conduction period for the switch according to the indication signal. The energy-recycling circuit is coupled to a first capacitive component and a second capacitive component. The energy-recycling circuit comprises the inductor and the switch coupled between the first capacitive component and the second capacitive component. The control signal generator determines the second conduction period according to the first conduction period and the indication signal.

Circuit and method of adjusting conduction period for energy-recycling circuit

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.

Demodulation signal generator for air pulse generator

A driving circuit comprises a first capacitor. During a sampling operation, the first capacitor is coupled between a first and a second input terminals. During a transferring operation, an end of the first capacitor receives a voltage and another end of the first capacitor is coupled to a load. The driving circuit produces a first driving signal to drive the load, the first driving signal comprises a plurality of first portions with a first polarity and a plurality of second portions with a second polarity opposite to the first polarity. The plurality of first portions and the plurality of second portions form a generalized DSB-SC modulated component of the first driving signal, which is modulated according to an input signal between the first input terminal and the second input terminal.

Driving circuit producing DSB-SC modulation signal

A driving circuit, configured to drive a venting device, includes a first node, a second node, and an amplifying circuit. The venting device, configured to be controlled to open a vent or seal the vent, includes a film structure, which includes a first flap and a second flap, and an actuator, which includes a first actuating portion disposed on the first flap and a second actuating portion disposed on the second flap. When the venting device is controlled to open the vent, the driving circuit generates a first voltage at the first node and generates a second voltage at the second node. When the venting device is controlled to seal the vent, the driving circuit generates a third voltage at both the first node and the second node. The first voltage is larger than the third voltage, and the third voltage is larger than the second voltage.

Driving circuit and wearable sound device thereof

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.

Feedback control system achieving high performance via density modulation

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.

Method of reducing conduction loss and switching loss applied in driving circuit and driving circuit using the same

A bidirectional charging and discharging circuit is coupled between a voltage source and a capacitive load and configured to drive the capacitive load. The bidirectional charging and discharging circuit includes a first switch, comprising a first terminal coupled to the voltage source; a second switch, comprising a first terminal coupled to a second terminal of the first switch, and a second terminal coupled to a ground; an inductor, comprising a first terminal coupled to the second terminal of the first switch and the first terminal of the second switch; a third switch, comprising a first terminal coupled to a second terminal of the inductor, and a second terminal coupled to a first terminal of the capacitive load; and a fourth switch, comprising a first terminal coupled to the second terminal of the inductor and the first terminal of the third switch, and a second terminal coupled to a ground.

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San Jose, CA, United States of America

Jing-Meng Liu