Control device for aerosol inhalation device includes operational amplifier for performing output according to voltage applied to load for heating aerosol source and having correlation between temperature and electrical resistance value, control unit for performing processing based on the voltage according to the output, diode having anode electrically connected to one of inverting input terminal and noninverting input terminal, and circuit for electrically connecting power supply and the load. The circuit is formed by first region, and second region in which maximum voltage is lower than that in the first region, or applied voltage is lower than that to the first region. Of the inverting input terminal and the noninverting input terminal, terminal to which the anode of the diode is electrically connected is electrically connected to the first region.

Control device for aerosol inhalation device, includes operational amplifier including output terminal configured to generate voltage according to voltage applied to load configured to heat aerosol source and having correlation between temperature and electrical resistance value, control unit including input terminal and configured to perform processing based on voltage applied to the input terminal, and voltage dividing circuit configured to electrically connect the output terminal of the operational amplifier and the input terminal of the control unit. Power supply voltage of the operational amplifier is higher than power supply voltage of the control unit, and equals voltage applied to aerosol generation circuit including the load, and one of inverting input terminal and noninverting input terminal of the operational amplifier is electrically connected to the aerosol generation circuit.

This application provides a power adjustment method and apparatus. The method includes obtaining a to-be-output signal, performing first automatic gain control (AGC) processing on the to-be-output signal to obtain the to-be-output signal on which the first AGC processing is performed, and to obtain a gain value of the to-be-output signal. The method also includes performing digital pre-distortion (DPD) processing on the to-be-output signal on which the first AGC processing is performed, to obtain the to-be-output signal on which the DPD processing is performed. The method further includes calculating an output power back-off (OBO) value based on the gain value, adjusting, based on the OBO value, output power of the to-be-output signal on which the DPD processing is performed, and sending, to a signal receive end, the to-be-output signal on which the power adjustment is performed.

A power amplifier (20) for a transmitter circuit (10) is disclosed. The power amplifier (20) comprises at least one field-effect transistor (100, 100n, 100p) having a gate terminal (110, 110n, 110p) and a bulk terminal (120, 120n, 120p), wherein the at least one field-effect transistor (100, 100n, 100n) is configured to receive an input voltage at the gate terminal (110, 110p, 110n) and a dynamic bias voltage at the bulk terminal (120, 120n, 120p). Furthermore, the power amplifier (20) comprises a bias-voltage generation circuit (130). The input voltage is a linear function of an input signal. The bias-voltage generation circuit (130) is configured to generate the dynamic bias voltage as a nonlinear function of an envelope of the input signal.

A system includes an amplification circuit and offset calibration circuit. The amplification circuit includes a modulation circuit operable to modulate a received signal, an amplifier operable to amplify the modulated signal, and a modulation circuit operable to demodulate the amplified signal. The offset calibration circuit includes a logic circuit operable to set a control signal and adjust the control signal based on an output of the amplification circuit, where the output is based on the demodulated signal, and a compensation signal generator operable to generate a compensation signal based on the control signal to compensate for an offset associated with the amplification circuit, and apply the compensation signal on the amplification circuit to adjust the output of the amplification circuit. The offset calibration circuit in conjunction with the application circuit reduces flicker, offset, and offset drift, and also suppresses the upmodulate ripple due to chopping.

In accordance with embodiments of the present disclosure, a system may include a buffer and a switch coupled between the buffer and a voltage supply such that the switch controls a varying voltage at a varying voltage node coupled to the buffer.

An impedance measurement circuit for determining a sense current of a guard-sense capacitive sensor operated in loading mode. The circuit includes a periodic signal voltage source for providing a periodic measurement voltage, a sense current measurement circuit, a differential amplifier that is configured to sense a complex voltage difference between the sense electrode and the guard electrode, a demodulator for obtaining, with reference to the periodic measurement voltage, an in-phase component and a quadrature component of the sensed complex voltage difference, and control loops for receiving the in-phase component and the quadrature component, respectively. An output signal of the first control loop and an output signal of the second control loop are usable to form a complex voltage that serves as a complex reference voltage for the sense current measurement circuit.

An envelope tracking (ET) amplifier apparatus is provided. The ET amplifier apparatus includes an amplifier circuit configured to amplify a radio frequency (RF) signal based on a modulated voltage. In examples discussed herein, the amplifier circuit is co-located with a local voltage amplifier circuit configured to supply the modulated voltage such that a trace inductance between the amplifier circuit and the local voltage amplifier circuit can be reduced to below a defined threshold. By co-locating the amplifier circuit with the local voltage amplifier circuit to reduce a coupling distance between the amplifier circuit and the local voltage amplifier circuit and thus the trace inductance associated with the coupling distance, it may be possible to reduce degradation in the modulated voltage. As a result, it may be possible to improve efficiency and maintain linearity in the amplifier circuit, particularly when the RF signal is modulated at a higher modulation bandwidth.

Systems, methods, and circuitries are provided for generating a power amplifier supply voltage based on a target envelope signal for a radio frequency (RF) transmit signal. An envelope tracking system includes a first selector circuitry and predistortion circuitry. The first selector circuitry is disposed in a selector module and is configured to input a plurality of voltages conducted on a first plurality of power lanes, wherein the first plurality of power lanes is part of a power distribution network; select a voltage from the plurality of voltages based on the target envelope signal; and provide the selected voltage to a supply lane connected to an input of the power amplifier that amplifies the RF transmit signal. The predistortion circuitry is configured to modify the RF transmit signal based on a selected power lane of the first plurality of power lanes that conducts the selected voltage.

Apparatus and methods for power amplifiers with positive envelope feedback are provided herein. In certain implementations, a power amplifier system includes a power amplification stage that amplifies a radio frequency signal, at least one envelope detector that generates one or more detection signals indicating an output signal envelope of the power amplification stage, and a wideband feedback circuit that provides positive envelope feedback to a bias of the power amplification stage based on the one or more detection signals. The power amplifier system further includes a supply modulator that controls a voltage level of a supply voltage of the power amplification stage based on the one or more detection signals such that the supply voltage is modulated with the output signal envelope through positive envelope feedback.