Abstract: A circuit and a method for controlling an audio adapter are provided. The audio adapter includes a button and a microphone, and the microphone is adapted for generating a recorded data. The control circuit includes a button detection circuit, a first-in, first-out (FIFO) data buffer, a USB endpoint buffer, a mute circuit and a USB endpoint control circuit. The button detection circuit is used for detecting whether the button is triggered. The FIFO data buffer is used for storing the recorded data. The USB endpoint buffer is used for storing the recorded data. The mute circuit is used for controlling whether the recorded data is transmitted to the USB endpoint buffer according to whether the button is triggered. The USB endpoint control circuit is used for controlling whether the audio adapter outputs the recorded data according to whether the button is triggered.

Abstract: An external audio device includes a USB (Universal Serial Bus) plug, an audio socket, a USB communication circuit, an audio socket detection circuit, a first power circuit, a second power circuit, and a control circuit. The USB communication circuit establishes a connection with a computer device coupled to the USB plug according to the communication protocol of USB. The audio socket detection circuit detects a plug-in state of the audio socket. The first power circuit generates a second power to the USB communication circuit according to a first power received from the USB plug. The second power circuit generates a third power to the audio socket detection circuit according to the first power. The control circuit enables or disables the first power circuit according to the plug-in state of the audio socket.

Abstract: A circuit and a method for controlling an audio adapter are provided. The audio adapter includes a button and a microphone, and the microphone is adapted for generating a recorded data. The control circuit includes a button detection circuit, a first-in, first-out (FIFO) data buffer, a USB endpoint buffer, a mute circuit and a USB endpoint control circuit. The button detection circuit is used for detecting whether the button is triggered. The FIFO data buffer is used for storing the recorded data. The USB endpoint buffer is used for storing the recorded data. The mute circuit is used for controlling whether the recorded data is transmitted to the USB endpoint buffer according to whether the button is triggered. The USB endpoint control circuit is used for controlling whether the audio adapter outputs the recorded data according to whether the button is triggered.

Abstract: An electronic apparatus comprises a switch, a processing unit, a functional unit and a power management unit. The function unit has a timer. The power management unit is coupled to the processing unit and the function unit. The processing unit and the function unit receive a switch signal generated by the switch. The processing unit generates a power-down signal after detecting a change in the logic level of the switch signal received for a first predetermined time. The timer starts counting upon detecting a change in the logic level of the switch signal, and executes a power-down procedure after the timer has counted to a second predetermined time. The second time is less than the first predetermined time. The function unit completes the power-down procedure before the power management unit receives the power-down signal and stops powering the processing unit and the function unit.

Abstract: The present invention provides a signal processing circuit and a signal processing method applied to a headset. In the present invention, the signal processing circuit adjusts gain and phase of a left channel signal and a right channel signal to generate a first adjust signal, and a recorded sound from a microphone is added by the first adjust signal to cancel a coupled signal. In addition, the signal processing circuit adjusts gain and phase of the right channel signal to generate a second adjust signal, and the right channel signal is added by the second adjust signal to cancel a coupled signal; and the signal processing circuit adjusts gain and phase of the left channel signal to generate a third adjust signal, and the left channel signal is added by the third adjust signal to cancel a coupled signal.

Abstract: The present invention discloses an audio device having haptic compensation function capable of compensating a haptic effect according to a power measuring result and an audio signal. An embodiment of the audio device comprises: an audio signal generating circuit operable to generate an audio signal; a power measuring circuit operable to measure a remaining electric quantity of a power source and thereby generate a power measuring result; and a haptic compensating circuit, coupled to the audio signal generating circuit and the power measuring circuit, operable to adjust a gain of the audio signal or the derived signal thereof according to the power measuring result and thereby output a haptic compensation signal which is used to compensate the haptic effect.

Abstract: The present invention discloses an electronic device using pulse density modulation for communication, comprising: a pulse density modulation interface; a first circuit to output a clock signal and a data signal through the pulse density modulation interface; and a second circuit to receive the clock and data signals and thereby determine whether the level change times of the data signal reach a predetermined threshold while the clock signal remains unchanged, so as to verify whether the clock and data signals satisfy a start protocol. In an embodiment of the present invention, the above-mentioned predetermined threshold is equal to or more than three.

Abstract: An electronic apparatus comprises a switch, a processing unit, a functional unit and a power management unit. The function unit has a timer. The power management unit is coupled to the processing unit and the function unit. The processing unit and the function unit receive a switch signal generated by the switch. The processing unit generates a power-down signal after detecting a change in the logic level of the switch signal received for a first predetermined time. The timer starts counting upon detecting a change in the logic level of the switch signal, and executes a power-down procedure after the timer has counted to a second predetermined time. The second time is less than the first predetermined time. The function unit completes the power-down procedure before the power management unit receives the power-down signal and stops powering the processing unit and the function unit.

Abstract: The present invention provides a signal processing circuit and a signal processing method applied to a headset. In the present invention, the signal processing circuit adjusts gain and phase of a left channel signal and a right channel signal to generate a first adjust signal, and a recorded sound from a microphone is added by the first adjust signal to cancel a coupled signal. In addition, the signal processing circuit adjusts gain and phase of the right channel signal to generate a second adjust signal, and the right channel signal is added by the second adjust signal to cancel a coupled signal; and the signal processing circuit adjusts gain and phase of the left channel signal to generate a third adjust signal, and the left channel signal is added by the third adjust signal to cancel a coupled signal.

Abstract: The present invention discloses an audio device having haptic compensation function capable of compensating a haptic effect according to a power measuring result and an audio signal. An embodiment of the audio device comprises: an audio signal generating circuit operable to generate an audio signal; a power measuring circuit operable to measure a remaining electric quantity of a power source and thereby generate a power measuring result; and a haptic compensating circuit, coupled to the audio signal generating circuit and the power measuring circuit, operable to adjust a gain of the audio signal or the derived signal thereof according to the power measuring result and thereby output a haptic compensation signal which is used to compensate the haptic effect.

Abstract: The present invention discloses an electronic device using pulse density modulation for communication, comprising: a pulse density modulation interface; a first circuit to output a clock signal and a data signal through the pulse density modulation interface; and a second circuit to receive the clock and data signals and thereby determine whether the level change times of the data signal reach a predetermined threshold while the clock signal remains unchanged, so as to verify whether the clock and data signals satisfy a start protocol. In an embodiment of the present invention, the above-mentioned predetermined threshold is equal to or more than three.

Abstract: An audio processing chip includes a connecting port, an audio amplifier module and a pulse width modulation (PWM) control circuit. The connecting port receives a pulse width modulation (PWM) signal; the audio amplifier module amplifies an audio signal according to a control signal to thereby output an audio output signal; and the pulse width modulation (PWM) control circuit is coupled between the connecting port and the audio amplifier module, and outputs the control signal to the audio amplifier module according to the PWM signal to thereby control an operation of the audio amplifier module.

Abstract: An audio processing chip includes a connecting port, an audio amplifier module and a pulse width modulation (PWM) control circuit. The connecting port receives a pulse width modulation (PWM) signal; the audio amplifier module amplifies an audio signal according to a control signal to thereby output an audio output signal; and the pulse width modulation (PWM) control circuit is coupled between the connecting port and the audio amplifier module, and outputs the control signal to the audio amplifier module according to the PWM signal to thereby control an operation of the audio amplifier module.

Abstract: A test circuit, for checking whether at least one programmable gain amplifier (PGA) operates correctly, includes a signal generator, a gain controller, a test level output circuit, a comparison circuit and an identifying circuit. The signal generator is utilized for outputting a test input signal to a PGA to generate a test output signal. The gain controller is utilized for outputting a gain control signal to the PGA to adjust a gain of the PGA. The test level output circuit is utilized for referring to the test output signal to output a first test level and a second test level. The comparison circuit is utilized for comparing the first and second test levels to generate a result signal. The identifying circuit is utilized for identifying whether the PGA operates correctly according to the result signal.

Abstract: A test circuit, for checking whether at least one programmable gain amplifier (PGA) operates correctly, includes a signal generator, a gain controller, a test level output circuit, a comparison circuit and an identifying circuit. The signal generator is utilized for outputting a test input signal to a PGA to generate a test output signal. The gain controller is utilized for outputting a gain control signal to the PGA to adjust a gain of the PGA. The test level output circuit is utilized for referring to the test output signal to output a first test level and a second test level. The comparison circuit is utilized for comparing the first and second test levels to generate a result signal. The identifying circuit is utilized for identifying whether the PGA operates correctly according to the result signal.