Abstract: Provided herein are a headphone amplifier circuit for a headphone driver, an operation method thereof, and a universal serial bus (USB) interfaced headphone device using the same. The output stage of the headphone amplifier circuit is improved to have a differential output structure so as to effectively solve the crosstalk issue and increase the isolation between the left and the right channels such that the audio content presents a spatial perception and a distance perception more specifically.

Abstract: Provided herein are a headphone amplifier circuit for a headphone driver, an operation method thereof, and a universal serial bus (USB) interfaced headphone device using the same. The output stage of the headphone amplifier circuit is improved to have a differential output structure so as to effectively solve the crosstalk issue and increase the isolation between the left and the right channels such that the audio content presents a spatial perception and a distance perception more specifically.

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 discloses an audio codec with a jack detection function and an audio jack detection method. An embodiment of the audio codec comprises: a first-contact signal input end operable to electrically connect with a sleeve contact of a plug and receive a first-contact signal indicating the presence or absence of the plug; a second-contact signal input end operable to electrically connect with a ring contact or the sleeve contact of the plug and receive a second-contact signal indicating the presence or absence of the plug; a plug detecting circuit coupled to the first-contact or second-contact signal input end and operable to detect whether a voltage level of the first-contact or second-contact signal has changed to thereby generate a plug detection signal; and a control circuit coupled to the plug detecting circuit and operable to determine the presence or absence of the plug according to the plug detection signal.

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: A button control method for a built-in audio codec of a portable electronic apparatus, and the button control method includes the following steps. A plurality of button signals generated by a button unit is first detected during a button detection period. Next, the button signals are sequentially recorded during the button detection period. The processing unit matches and identifies the button signals provided thereto to generate a control command accordingly to correspondingly control the portable electronic apparatus.

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 codec with a jack detection function and an audio jack detection method. An embodiment of the audio codec comprises: a first-contact signal input end operable to electrically connect with a sleeve contact of a plug and receive a first-contact signal indicating the presence or absence of the plug; a second-contact signal input end operable to electrically connect with a ring contact or the sleeve contact of the plug and receive a second-contact signal indicating the presence or absence of the plug; a plug detecting circuit coupled to the first-contact or second-contact signal input end and operable to detect whether a voltage level of the first-contact or second-contact signal has changed to thereby generate a plug detection signal; and a control circuit coupled to the plug detecting circuit and operable to determine the presence or absence of the plug according to the plug detection 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.