Abstract: A hybrid amplifier includes: a first to fourth PWM circuit, comparing triangular wave signals and filter signals to generate PWM signals; a first processing circuit, generating pulse-width processed signals based on the PWM signals and the polarity of input signals; a judgment circuit, generating a selection signal based on the level of a differential input signal; a selection circuit, generating switching control signals according to the selection signal and the pulse-width processed signals; and a first and second power stage generating switching voltages based on the switching control signals to switch an inductor to generate output signals. When outside the light-load range, the first switching signal controls the switching voltage to toggle between a higher voltage level and ground, while the second switching signal approximates the fundamental frequency. When within the light-load range, the switching control signals control the switching voltage to toggle between a lower voltage level and ground.

Abstract: A hybrid differential amplifier generating a differential output signal based on a differential input signal having a fundamental frequency includes: a first amplifier configured as an inductive switching converter; and a second amplifier configured as another type of amplifier. The first and second amplifiers respectively generate first and second output signals of the differential output signal based on first and second input signals of the differential input signal. One of the first or second amplifiers further generates the first or second output signal based on feedback, thereby the differential output signal is linearly related to the differential input signal. The other amplifier performs a quantization processing on the first or second input signal, thereby the second output signal includes a staircase wave related to the fundamental frequency. The quantization processing includes generating a quantized output signal based on the first or second input signal and at least one threshold level.

Abstract: A hybrid differential amplifier that generates a differential output signal based on a differential input signal to drive a load, includes: a first amplifier configured as an inductive switching converter to perform pulse-width modulation (PWM) conversion based on a first input signal of the differential input signal to switch an inductor and generate a first output signal of the differential output signal; and a second amplifier configured to generate a second output signal of the differential output signal based on a second input signal of the differential input signal. The second amplifier is configured as a different type of amplifier distinct from the inductive switching converter. The second amplifier further generates the second output signal based on feedback from the differential output signal, thereby the differential output signal being linearly correlated with the differential input signal.

Abstract: A class-D amplifying system includes: a class-D amplifier circuit configured to convert an input signal to a switch control signal in pulse width modulation fashion, wherein the switch control signal controls switches to operate a first inductor and a second inductor, thus converting an input power to a positive output signal and a negative output signal which are complementary to each other, to thereby drive a load; and a power converter circuit, which generates a direct current (DC) power supply according to at least one of the positive output signal and the negative output signal, wherein the DC power supply supplies at least a portion of power to the class-D amplifier circuit.

Abstract: An electronic device includes two speakers, a single functional chip, a parameter extraction circuit, an audio processing module, a gain adjusting circuit and a current detecting unit. The current detecting unit is disposed in the functional chip for detecting the driving current of the two speakers. The functional chip provides the driving voltage of the two speakers based on an output signal and converts the analogue current/voltages of the two speakers into digital current/voltages. The parameter extraction circuit acquires the parameter of each speaker based on the digital current/voltages. The audio processing module acquires the gains of various physical quantities based on the parameter of each speaker and determines the final gain of each physical quantity. The gain adjusting circuit provides the output signal by adjusting the gain of an input signal based on the final gain of each physical quantity.

Abstract: An electronic device for controlling an LRA (Linear Resonant Actuator) includes a signal generator, a driver, a delay unit, a sensor, and a DSP (Digital Signal Processor). The signal generator generates a digital signal. The driver drives the LRA according to the digital signal. The delay unit delays the digital signal for a predetermined time, so as to generate an estimated voltage signal. The sensor detects the current flowing through the LRA, so as to generate a sensing current signal. The DSP controls the resonant frequency or the gain value of the signal generator according to the estimated voltage signal and the sensing current signal.

Abstract: An electronic device includes two speakers, a single functional chip, a parameter extraction circuit, an audio processing module, a gain adjusting circuit and a current detecting unit. The current detecting unit is disposed in the functional chip for detecting the driving current of the two speakers. The functional chip provides the driving voltage of the two speakers based on an output signal and converts the analogue current/voltages of the two speakers into digital current/voltages. The parameter extraction circuit acquires the parameter of each speaker based on the digital current/voltages. The audio processing module acquires the gains of various physical quantities based on the parameter of each speaker and determines the final gain of each physical quantity. The gain adjusting circuit provides the output signal by adjusting the gain of an input signal based on the final gain of each physical quantity.

Abstract: A calibration method is configured for calibrating an operation circuit which has a variant offset. The operation circuit includes at least one comparator circuit having a first variant offset. The calibration method provides an adjustable offset to calibrate the variant offset. The method includes: resetting an adjustment parameter to an initial value and configuring the operation circuit to a calibration mode; conducting an initial calibration procedure according to a comparison result of the comparator circuit, to decide an operation calibration code having plural bits; configuring the operation circuit to an operation mode; conducting a predetermined operation procedure according to the operation calibration code, wherein the operation calibration code corresponds to the adjustable offset; conducting a less bit number calibration procedure according to the adjustment parameter and a test calibration code to update the adjustment parameter or the operation calibration code; and repeating the above.

Abstract: A BD type pulse width modulation (PWM) circuit is configured to convert a pair of complementary input signals to a pair of output PWM signals. The BD PWM circuit modulates a basic modulation signal according to the pair of input signals, to generate a basic PWM signal. The common mode levels of the pair of input signals and the basic modulation signal are the same. The BD PWM circuit modulates an offset modulation signal according to the pair of input signals to generate an offset PWM signal. The offset modulation signal and the basic modulation signal have a non-zero offset in between. The BD PWM circuit selects the offset PWM signal or a heavy load PWM signal as the pair of output PWM signals. The heavy load PWM signal is correlated with the basic PWM signal.

Abstract: An electronic device includes two speakers, a single functional chip, a parameter extraction circuit, an audio processing module, a gain adjusting circuit and a current detecting unit. The current detecting unit is disposed in the functional chip for detecting the driving current of the two speakers. The functional chip provides the driving voltage of the two speakers based on an output signal and converts the analogue current/voltages of the two speakers into digital current/voltages. The parameter extraction circuit acquires the parameter of each speaker based on the digital current/voltages. The audio processing module acquires the gains of various physical quantities based on the parameter of each speaker and determines the final gain of each physical quantity. The gain adjusting circuit provides the output signal by adjusting the gain of an input signal based on the final gain of each physical quantity.

Abstract: A foreign object detection method for detecting whether a foreign object exists on a function pin of a power supplier side or a power receiver side, wherein the power supplier side and the power receiver side are coupled to each other in a detachable fashion. The foreign object detection method includes: discharging a capacitor via the function pin, wherein the capacitor is electrically connected to the function pin; providing a sensing current flowing through the function pin, to charge the capacitor; sensing a voltage variation of the function pin during a predetermined period; and comparing the voltage variation with a predetermined variation, so as to determine whether a foreign object exists on the function pin.

Abstract: A calibration method is configured for calibrating an operation circuit which has a variant offset. The operation circuit includes at least one comparator circuit having a first variant offset. The calibration method provides an adjustable offset to calibrate the variant offset. The method includes: resetting an adjustment parameter to an initial value and configuring the operation circuit to a calibration mode; conducting an initial calibration procedure according to a comparison result of the comparator circuit, to decide an operation calibration code having plural bits; configuring the operation circuit to an operation mode; conducting a predetermined operation procedure according to the operation calibration code, wherein the operation calibration code corresponds to the adjustable offset; conducting a less bit number calibration procedure according to the adjustment parameter and a test calibration code to update the adjustment parameter or the operation calibration code; and repeating the above.

Abstract: An electronic device for controlling an LRA (Linear Resonant Actuator) includes a signal generator, a driver, a delay unit, a sensor, and a DSP (Digital Signal Processor). The signal generator generates a digital signal. The driver drives the LRA according to the digital signal. The delay unit delays the digital signal for a predetermined time, so as to generate an estimated voltage signal. The sensor detects the current flowing through the LRA, so as to generate a sensing current signal. The DSP controls the resonant frequency or the gain value of the signal generator according to the estimated voltage signal and the sensing current signal.

Abstract: A class-D amplifying system includes: a class-D amplifier circuit configured to convert an input signal to a switch control signal in pulse width modulation fashion, wherein the switch control signal controls switches to operate a first inductor and a second inductor, thus converting an input power to a positive output signal and a negative output signal which are complementary to each other, to thereby drive a load; and a power converter circuit, which generates a direct current (DC) power supply according to at least one of the positive output signal and the negative output signal, wherein the DC power supply supplies at least a portion of power to the class-D amplifier circuit.

Abstract: A foreign object detection method for detecting whether a foreign object exists on a function pin of a power supplier side or a power receiver side, wherein the power supplier side and the power receiver side are coupled to each other in a detachable fashion. The foreign object detection method includes: discharging a capacitor via the function pin, wherein the capacitor is electrically connected to the function pin; providing a sensing current flowing through the function pin, to charge the capacitor; sensing a voltage variation of the function pin during a predetermined period; and comparing the voltage variation with a predetermined variation, so as to determine whether a foreign object exists on the function pin.

Abstract: A BD type pulse width modulation (PWM) circuit is configured to convert a pair of complementary input signals to a pair of output PWM signals. The BD PWM circuit modulates a basic modulation signal according to the pair of input signals, to generate a basic PWM signal. The common mode levels of the pair of input signals and the basic modulation signal are the same. The BD PWM circuit modulates an offset modulation signal according to the pair of input signals to generate an offset PWM signal. The offset modulation signal and the basic modulation signal have a non-zero offset in between. The BD PWM circuit selects the offset PWM signal or a heavy load PWM signal as the pair of output PWM signals. The heavy load PWM signal is correlated with the basic PWM signal.

Abstract: A low distortion triangular wave generator circuit generates a triangular wave signal by performing integration on an integration capacitor via a charging current and a discharging current during a charging period and a discharging period within a switching period of an external clock signal. A time length of the charging period is identical to a time length of the discharging period. A common mode related signal related to a common mode characteristic of the triangular wave signal is generated. An adjusting signal is generated according to a difference between the common mode related signal and a predetermined DC (direct current) level. The adjusting signal adjusts at least one of the charging current and the discharging current via feedback mechanism such that the triangular wave signal is a symmetrical triangular wave, and an average voltage of the triangular wave signal is equal to a target DC level.

Abstract: A low distortion triangular wave generator circuit generates a triangular wave signal by performing integration on an integration capacitor via a charging current and a discharging current during a charging period and a discharging period within a switching period of an external clock signal. A time length of the charging period is identical to a time length of the discharging period. A common mode related signal related to a common mode characteristic of the triangular wave signal is generated. An adjusting signal is generated according to a difference between the common mode related signal and a predetermined DC (direct current) level. The adjusting signal adjusts at least one of the charging current and the discharging current via feedback mechanism such that the triangular wave signal is a symmetrical triangular wave, and an average voltage of the triangular wave signal is equal to a target DC level.

Abstract: A DAC circuit includes: a PWM encoding circuit for converting a digital signal to first and second PWM signals, whereby a combination of the first and second PWM signals becomes a PWM encoded signal of at least 3 levels including a positive, a zero and a negative level, wherein the digital signal represents a number in a numerical range; and a demodulation circuit for generating the analog signal according to the first and second PWM signals. The first and second PWM signals have a minimum duty larger than 0 when the digital signal represents a middle number in the numerical range. The zero level of the combination of the first and second PWM signals has a duty which decreases as a difference between the number represented by the digital signal and the middle number increases.

Abstract: A voltage adjusting circuit includes a reference voltage generating circuit, a subtractor circuit, a threshold generating circuit and a comparator circuit. The voltage adjusting circuit may provide power supply signals to an amplifier circuit so that the amplifier circuit may provide an output signal to a load according to an input signal. The subtractor circuit generates a difference signal according to the output signal and the power supply signal. The comparator circuit compares the difference signal and a threshold signal generated by the threshold generating circuit for configuring the reference voltage generating circuit to adjust the signal value of the power supply signal.