A flip-chip semiconductor-on-insulator die includes a substrate layer, an active layer, an insulator layer between the substrate layer and the active layer, a first metal layer, and a first via layer between the active layer and the first metal layer. The die at least first and second contact pads and a transistor including a first terminal formed within the active layer. A first portion of the first terminal falls within a footprint of the first contact pad and a second portion of the first terminal falls within a footprint of the second contact pad.

A flip-chip semiconductor-on-insulator die includes a substrate layer, an active layer, an insulator layer between the substrate layer and the active layer, a first metal layer, and a first via layer between the active layer and the first metal layer. The die at least first and second contact pads and a transistor including a first terminal formed within the active layer. A first portion of the first terminal falls within a footprint of the first contact pad and a second portion of the first terminal falls within a footprint of the second contact pad.

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 packaged semiconductor chip includes a semiconductor sub strate having formed thereon: radio-frequency (RF) input and output contact pads, DC contact pads, and first and second amplifier stages. An input of the first amplifier stage is coupled with the RF input contact pad. An input and an output of the second amplifier stage are respectively coupled to an output of the first amplifier stage and the RF output contact pad. The DC contact pads and the input of the first amplifier stages are connected via an input bias coupling path. The outputs of the amplifier stages are connected via an output bias coupling path. The chip further includes a lead frame having RF input and output pins electrically coupled to the RF input and output contact pads, and input bias pins electrically coupled to the DC contact pad.

A packaged semiconductor chip includes a semiconductor sub strate having formed thereon: radio-frequency (RF) input and output contact pads, DC contact pads, and first and second amplifier stages. An input of the first amplifier stage is coupled with the RF input contact pad. An input and an output of the second amplifier stage are respectively coupled to an output of the first amplifier stage and the RF output contact pad. The DC contact pads and the input of the first amplifier stages are connected via an input bias coupling path. The outputs of the amplifier stages are connected via an output bias coupling path. The chip further includes a lead frame having RF input and output pins electrically coupled to the RF input and output contact pads, and input bias pins electrically coupled to the DC contact pad.

A high frequency RF power transistor includes first and second elongated mesas. In one example, the transistor is part of a millimeter wave MMIC power amplifier. From the top-down perspective, the two mesas are disposed in an off-axis and staggered orientation with respect to one another. A branched gate electrode is formed such that a first branch from a gate signal input location to the first mesa is the same length as a second branch from the input location to the second mesa. Likewise, a branched drain electrode is formed such that a first branch from the first mesa to a drain signal output location is the same length as a second branch from the second mesa to the output location. The off-axis and staggered orientation of the mesas spreads heat generation across the integrated circuit and reduces circuit size in the critical dimension perpendicular to signal flow direction.

Bias circuits and methods for silicon-based amplifier architectures that are tolerant of supply and bias voltage variations, bias current variations, and transistor stack height, and compensate for poor output resistance characteristics. Embodiments include power amplifiers and low-noise amplifiers that utilize a cascode reference circuit to bias the final stages of a cascode amplifier under the control of a closed loop bias control circuit. The closed loop bias control circuit ensures that the current in the cascode reference circuit is approximately equal to a selected multiple of a known current value by adjusting the gate bias voltage to the final stage of the cascode amplifier. The final current through the cascode amplifier is a multiple of the current in the cascode reference circuit, based on a device scaling factor representing the relative sizes of the transistor devices in the cascode amplifier and in the cascode reference circuit.