A nicotine delivery device (200) for generating a mist containing nicotine for inhalation by a user. The device comprises a mist generator device (201) and a driver device (202). The driver device (202) is configured to drive the mist generator device (201) at an optimum frequency to maximise the efficiency of mist generation by the mist generator device (201).

A digital to analog converter (DAC) includes a first amplifier configured to receive a first bit of a data block as an input and output a first signal based on a value of the first bit of the data block, a first filter circuit configured to filter the first signal, an output configured to output an analog signal based on a combination of the filtered first signal and a second signal that represents a value of a second bit of the data block.

A digital to analog converter (DAC) includes a first amplifier configured to receive a first bit of a data block as an input and output a first signal based on a value of the first bit of the data block, a first filter circuit configured to filter the first signal, an output configured to output an analog signal based on a combination of the filtered first signal and a second signal that represents a value of a second bit of the data block.

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.

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.

An interpolation filtering system implemented by a digital circuit is provided, it includes an interpolation filtering operation controller, a cascaded drive module, an intermediate result cache Random Access Memory (RAM), and a filter coefficient storage Read Only Memory (ROM). The intermediate result cache RAM is configured to store externally input data of the interpolation filtering system and intermediate results output by the filter operation modules. The filter coefficient storage ROM is configured to store filter coefficients required for calculation by the filter operation modules. The interpolation filtering operation controller is configured to control, under the drive of counting beats output by the cascaded drive module, the master state machine to select data of the intermediate result cache TAM or externally directly input data to be sent to the cascaded filter operation modules for accumulation operation, and to select the filter coefficients of the filter coefficient storage ROM for multiplication operation.

An interpolation filtering system implemented by a digital circuit is provided, it includes an interpolation filtering operation controller, a cascaded drive module, an intermediate result cache Random Access Memory (RAM), and a filter coefficient storage Read Only Memory (ROM). The intermediate result cache RAM is configured to store externally input data of the interpolation filtering system and intermediate results output by the filter operation modules. The filter coefficient storage ROM is configured to store filter coefficients required for calculation by the filter operation modules. The interpolation filtering operation controller is configured to control, under the drive of counting beats output by the cascaded drive module, the master state machine to select data of the intermediate result cache TAM or externally directly input data to be sent to the cascaded filter operation modules for accumulation operation, and to select the filter coefficients of the filter coefficient storage ROM for multiplication operation.

Included are: a first power source 3 configured to output a voltage required for a first gate bias voltage for turning a power amplifier 2 to an ON state; a second power source 4 configured to output a voltage required for a second gate bias voltage for turning the power amplifier 2 to an OFF state; a changeover switch 5 connected between the first power source 3 and the power amplifier 2 and configured to supply either the first gate bias voltage or the second gate bias voltage to the power amplifier 2 by switching a state between the first power source 3 and the power amplifier 2 to either an open state or a short-circuit state on the basis of a control signal related to on-off control of the power amplifier 2; and a resistance value varying unit 15 connected between the second power source 4 and the power amplifier 2 and configured such that a resistance value thereof is variable.

The present invention, a Digital Power Amplifier (DPA) with filtered output relates to the transmission circuitry of wireless communications systems and more particularly to high frequency power amplifier circuits using digital intensive techniques on cost efficient semiconductor technologies. Today, we experience an ever-increasing need for low cost, low power wireless transmitters in the millimeter wavelength region. Current solutions rely on analog PA circuits. The background art does not contain a solution for bridging the gap between the operation frequencies of the digital circuits on a cost-efficient technology such as CMOS and the millimeter wavelength transmission frequencies demanded in numerous applications. The DPA allowing the direct feeding of digital data to a high frequency amplifying circuit. In this way, design challenging and costly analog processing up-conversion stages are avoided. The DPA comprises a bank of switching amplifying elements, a switch capacitor trap filter taping on the bank of switching amplifying elements for shaping the frequency characteristic of the produced radio frequency (RF) waveform and an adaptive biasing circuit able of dynamically controlling the power consumption within the switching amplifying elements. It can have a wide spectrum of applications where low cost but high efficiency power amplifiers are needed, such as in the Internet of Things (IoT), Wi-Fi and 5G cellular communications.

The invention concerns a circuit for transferring a data from one clock domain to another clock domain, the circuit comprising: a digital circuit configured to generate a data signal synchronized with a source clock signal, and to receive such data by sampling the data signal synchronized with a target clock signal; a phase comparator which is configured to determine a phase relationship between the source clock signal and the target clock signal; and a data signal synchronization circuit configured to receive data signal transitions that are synchronized with the source clock signal, and to provide a synchronized data signal transitions of which are synchronized with the target clock signal.