Abstract: An earphone jack drive circuit applied in an electronic device is provided. The earphone jack drive circuit includes a mute circuit; a micro-controller including a detect pin and a control pin; a delay switch circuit including a resistance, a capacitance, an npn transistor and a first current-limiting resistance. During the plugging in or the unplugging out of the earphone, any momentary logic high of the detect pin charges the capacitance, the capacitance discharges when the detect pin is set to be logic low. For a period, the npn transistor is kept on, the connector of the npn transistor is set to be logic low, the input port of the mute circuit is set to be logic low, thereby the mute circuit is controlled to perform the mute mode during the period to eliminate the popping noises of connection and disconnection.

Abstract: A wake-up circuit used in an electronic device, the electronic device comprising a power supply and a load. The wake-up circuit includes a receiving unit receiving a wake-up signal, a control unit continuously generating an enable signal for a first predetermined time period when the receiving unit receives the wake-up signal, a voltage converter, and a processing unit. The power supply provides a secondary voltage to the voltage converter when the electronic device is in the standby state; the voltage converter converts the secondary voltage to a working voltage in response to the enable signal. The processing unit is powered by the working voltage to generate the enable signal and output the enable signal to the voltage converter and generates a control signal when the processing unit determines that the wake-up signal is a power-on command, the control signal controls the power supply to power the load.

Abstract: A discharge circuit for increasing discharge time of battery includes a discharging IC and a delay discharge circuit. When the discharging IC detects any voltage input, a minimum operating voltage of the discharging IC is set to 6.3V, when the discharging IC detects no voltage input, the minimum operating voltage of the discharging IC is set to 5.5 V. The delay discharge circuit is connected with a system voltage via a first current-limiting resistance, to make the discharging IC unable to detect any voltage input when only a battery is used as power source, thereby the minimum operating voltage of the discharging IC is set to 5.5V.

Abstract: A mute drive circuit includes a micro-controller including an I/O port; a mute circuit; and an npn transistor. When an electronic device using the mute circuit is plugged into an AC power source, the I/O port is set to the logic low, the mute circuit performs the mute mode. When the electronic device is turned on, the I/O port is controlled set to the logic low for a period and then be pulled up to the logic high, the mute circuit performs the mute mode for the period and then enters into the normal mode. When the electronic device is turned off, the I/O port is controlled to set to the logic low, the mute circuit performs the mute mode. When the electronic device is unplugged from the AC power source, the I/O port is pulled down to the logic low, the mute circuit performs the mute mode.

Abstract: An earphone jack drive circuit applied in an electronic device is provided. The earphone jack drive circuit includes a mute circuit; a micro-controller including a detect pin and a control pin; a delay switch circuit including a resistance, a capacitance, an npn transistor and a first current-limiting resistance. During the plugging in or the unplugging out of the earphone, any momentary logic high of the detect pin charges the capacitance, the capacitance discharges when the detect pin is set to be logic low. For a period, the npn transistor is kept on, the connector of the npn transistor is set to be logic low, the input port of the mute circuit is set to be logic low, thereby the mute circuit is controlled to perform the mute mode during the period to eliminate the popping noises of connection and disconnection.