Bias circuits for CMOS power amplifiers are provided. The bias circuit includes a feedback module, a first bias module, and a second bias module. The feedback module has a first input connected to a output common mode voltage, a second input connected to a reference voltage, and an output connected to gates of main amplification transistors in a first differential amplification module; based on a difference between the output common mode voltage and the reference voltage, the feedback module adjusts gate voltages of main amplification transistors until the output common mode voltage is equal to the reference voltage; the first bias module provides bias voltages for the first differential amplification module; the second bias module provides bias voltages for a second differential amplification module. The present disclosure adopts direct negative feedback and cascoded current mirrors, which realize accurate DC gate bias and accurate control of the output common mode voltage.

Bias circuits for CMOS power amplifiers are provided. The bias circuit includes a feedback module, a first bias module, and a second bias module. The feedback module has a first input connected to a output common mode voltage, a second input connected to a reference voltage, and an output connected to gates of main amplification transistors in a first differential amplification module; based on a difference between the output common mode voltage and the reference voltage, the feedback module adjusts gate voltages of main amplification transistors until the output common mode voltage is equal to the reference voltage; the first bias module provides bias voltages for the first differential amplification module; the second bias module provides bias voltages for a second differential amplification module. The present disclosure adopts direct negative feedback and cascoded current mirrors, which realize accurate DC gate bias and accurate control of the output common mode voltage.

A driving circuit for an audio power amplifier and an electronic device are provided. The driving circuit includes an audio codec, an audio power amplifier (PA), a power management integrated circuit (PMIC), a transistor, a speaker, and a motor. The transistor is connected in series with the motor to form a combined body, the speaker is connected in parallel with the combined body to form a two-in-one device, the audio PA is connected in series with the two-in-one device, the PMIC is connected in series with the two-in-one device, and the audio codec is connected in series with the audio PA. In the technical solutions provided in embodiments of the disclosure, a power amplifier can drive both the motor and the speaker, so that a power amplifier may be omitted and the power consumption and cost of the electronic equipment may be reduced.

A driving circuit for an audio power amplifier and an electronic device are provided. The driving circuit includes an audio codec, an audio power amplifier (PA), a power management integrated circuit (PMIC), a transistor, a speaker, and a motor. The transistor is connected in series with the motor to form a combined body, the speaker is connected in parallel with the combined body to form a two-in-one device, the audio PA is connected in series with the two-in-one device, the PMIC is connected in series with the two-in-one device, and the audio codec is connected in series with the audio PA. In the technical solutions provided in embodiments of the disclosure, a power amplifier can drive both the motor and the speaker, so that a power amplifier may be omitted and the power consumption and cost of the electronic equipment may be reduced.

A tracker module is provided that includes a module substrate, an integrated circuit disposed on the module substrate, and a capacitor disposed on the module substrate and included in a switched-capacitor circuit. The switched-capacitor circuit generates multiple discrete voltages based on an input voltage. The integrated circuit includes a switch included in the switched-capacitor circuit and a switch included in an output switch circuit. The output switch circuit selectively outputs at least one of the multiple discrete voltages. The integrated circuit and the capacitor are adjacent to each other.

A tracker module is provided that includes a module substrate, an integrated circuit disposed on the module substrate, and a capacitor disposed on the module substrate and included in a switched-capacitor circuit. The switched-capacitor circuit generates multiple discrete voltages based on an input voltage. The integrated circuit includes a switch included in the switched-capacitor circuit and a switch included in an output switch circuit. The output switch circuit selectively outputs at least one of the multiple discrete voltages. The integrated circuit and the capacitor are adjacent to each other.

A tracker module includes a module laminate, a first integrated circuit and a second integrated circuit on the module laminate, and a capacitor disposed on the module laminate and included in a switched-capacitor circuit. The switched-capacitor circuit is configured to generate discrete voltages based on an input voltage. The first integrated circuit includes a switch included in the switched-capacitor circuit. The second integrated circuit includes a switch included in at least one of a supply modulator and a pre-regulator circuit. The supply modulator is configured to selectively output at least one of the discrete voltages based on an envelope signal. The pre-regulator circuit is configured to convert the input voltage into a first voltage and output the first voltage to the switched-capacitor circuit. A distance between the first integrated circuit and the capacitor is shorter than a distance between the second integrated circuit and the capacitor.

A tracker module includes an integrated circuit, a first capacitor and a second capacitor arranged in or on a module laminate. The integrated circuit includes at least one switch in a switched-capacitor circuit and at least one switch in a supply modulator. The switched-capacitor circuit is configured to generate a plurality of discrete voltages. The supply modulator is configured to generate an output voltage by selectively switching among the plurality of discrete voltages based on a control signal. The first capacitor is a flying capacitor of the switched-capacitor circuit. The second capacitor is a smoothing capacitor of the switched-capacitor circuit. In a plan view of the module laminate, the first capacitor is arranged closer to the integrated circuit than the capacitor.

A method of operating an amplifier circuit having a transformer arranged so as to establish a magnetically coupled feedback loop between and output of an amplifier and an input of the amplifier. The method includes providing a DC bias current to the amplifier, and further includes increasing the DC bias current to improve a linearity of the amplifier circuit wherein a transfer gain of the amplifier circuit remains constant when the DC bias current is increased. A loop gain of the magnetically coupled feedback loop is set by selecting a coupling factor and turn-ratio of the transformer.

Supply circuits, devices and methods related to radio-frequency amplifiers. In some embodiments, an amplification system can include an amplifier circuit having a plurality of stages and configured to amplify a signal. The amplification system can further include a supply circuit configured to provide a regulated supply voltage to at least one stage of the plurality of stages, and an unregulated supply voltage to at least one stage of the plurality of stages. In some embodiments, the amplifier circuit can be implemented as a power amplifier circuit.