Abstract: A power rectifier rectifies alternating electric current by using a controller in the power rectifier to control a first delay circuit in the power rectifier to turn on a high side switch in the power rectifier, wherein the high side switch provides a path for power from an input voltage line of the power rectifier to an output voltage line of the power rectifier. The controller controls a second delay circuit in the power rectifier to maintain the high side switch in an on state to change a switching state of the high side switch based on detection, by a current inversion detector, of a current inversion associated with the input and output voltage lines of the power rectifier.

Abstract: Aspects of the disclosure provide an apparatus having a first connector and a signal processing circuit. The first connector is configured to receive a second connector so that connecting terminals at respective portions of the first and second connectors are coupled together. The signal processing circuit is configured to generate a first output signal at a first amplification gain, determine a first load resistance value at a first connecting terminal of the second connector that is configured to receive the first output signal when coupled to the first connector, and set the first amplification gain based on the first load resistance value.

Abstract: A power rectifier rectifies alternating electric current by using a controller in the power rectifier to control a first delay corresponding to a first delay circuit in the power rectifier to turn on a high side switch in the power rectifier, wherein the high side switch provides a path for power from an input voltage line of the power rectifier to an output voltage line of the power rectifier. The controller controls a second delay corresponding to a second delay circuit in the power rectifier to maintain the high side switch in an on state so as to change a switching state of the high side switch based on detection, by a current inversion detector, of a current inversion associated with the input and output voltage lines of the power rectifier.

Abstract: Aspects of the disclosure provide an audio amplification system. The audio amplification system includes an amplifier configured to amplify an audio signal, and a power supply module external to the amplifier that is configured to provide to the amplifier a supply voltage having a voltage level that is selected from at least two possible voltage levels based on an output volume level for the audio signal. In an example, the amplifier is a Class AB amplifier.

Abstract: Aspects of the disclosure provide a circuit. The circuit includes a current generator, a capacitor, a comparator, a switch and a clock generator logic. The current generator is configured to generate a current proportional to a comparator threshold voltage by a ratio. The capacitor is configured to be charged by the current to have a capacitor voltage. The comparator is configured to compare the capacitor voltage with the comparator threshold voltage. The switch is configured to discharge the capacitor based on the comparison. The clock generator logic is configured to generate a clock signal based on the comparison, such that a frequency of the clock signal is a function of the ratio and is independent of the current and the comparator threshold voltage.

Abstract: In one embodiment, an RC oscillator is provided. The oscillator includes a current generator circuit configured to generate a current. A capacitor is configured to be charged by the current. An inverter includes an input coupled to the capacitor. An output of the inverter goes high when a voltage across the capacitor reaches a threshold voltage of the inverter. A switch coupled to the output of the inverter and the capacitor is configured to close when the output of the inverter goes high. This discharges the capacitor. The output of the inverter goes low when the capacitor is discharged and the switch is opened. Clock generator logic is configured to receive the output of the inverter and generate a clock signal. The current is proportional to the threshold voltage of the inverter.