A number of unit cells of a digital-to-analog converter (DAC) may be simultaneously activated to generate an analog signal according to a decoded digital signal. However, while many unit cells may be generally the same, there may be variations in the gains associated with each unit cell (e.g., based on the locations of the activated unit cells within a unit cell array) amounting to a gain gradient that may cause error in the analog output. As such, a fill order may be set or selected to counter such variation by activating a particular arrangement of unit cells, as opposed to simply the number of unit cells, for a given digital signal. By filling the unit cell array from different sides, spatially and/or temporally, the gain gradient associated with the unit cells may be balanced to reduce error and increase the linearity of the DAC.

A digital-to-analog conversion circuit (60) for converting a digital input sequence to an analog representation is disclosed. It comprises a first DAC, (100) wherein the first DAC (100) is of a capacitive voltage division type having a capacitive load (110). Furthermore, it comprises a second DAC (120) having a resistive load (130). An output (104) of the first DAC (100) and an output (124) of the second DAC (120) are connected, such that said capacitive load (110) and said resistive load (130) are connected in parallel.

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.

Provided is a fuel injection control device capable of improving detection accuracy of a singular point with respect to a characteristic of the fuel injection valve to be equal to or higher than an original time resolution of the A/D conversion, and capable of accurately detecting the singular point. A variable control part 24 variably controls a conversion timing of the A/D conversion part 221 such that the conversion timing of A/D conversion for physical quantity data related to driving of the fuel injection valve 10 is relatively changed, the A/D conversion part 221 acquires a plurality of time series data by performing A/D conversion on the physical quantity data at a conversion timing before change and at a conversion timing after change by the variable control part 24, and a detection part 223 detects a singular point with respect to the characteristic of the fuel injection valve 10 based on the plurality of time series data.

Provided is a fuel injection control device capable of improving detection accuracy of a singular point with respect to a characteristic of the fuel injection valve to be equal to or higher than an original time resolution of the A/D conversion, and capable of accurately detecting the singular point. A variable control part 24 variably controls a conversion timing of the A/D conversion part 221 such that the conversion timing of A/D conversion for physical quantity data related to driving of the fuel injection valve 10 is relatively changed, the A/D conversion part 221 acquires a plurality of time series data by performing A/D conversion on the physical quantity data at a conversion timing before change and at a conversion timing after change by the variable control part 24, and a detection part 223 detects a singular point with respect to the characteristic of the fuel injection valve 10 based on the plurality of time series data.

Disclosed are a method and a device for improving an output accuracy of a digital-to-analog converter. The method includes: calculating an output error of the digital-to-analog converter based on output accuracy and an input error of the digital-to-analog converter; obtaining at least one of the output error, comparing the at least one output error against a preset threshold, and adjusting an integer input value of the digital-to-analog converter according to a comparison result.

A double-balanced radio-frequency (RF) mixing digital-to-analog converter (DAC) apparatus includes a load network, a first set of resistive DAC driver circuits and a first mixing core. The first mixing core can receive first RF input signals from the first set of resistive DAC driver circuits and can provide a first mixed signal to the load network. The first mixing core includes a first input differential pair coupled to two first cross-coupled differential pairs. The first input differential pair can receive first RF input signals at respective first input nodes. Each of the two first cross-coupled differential pairs can receive first positive and negative local oscillator (LO) signals at corresponding first input nodes. The first mixing core can mix the first RF input signals with the first positive and negative LO signals.

A double-balanced radio-frequency (RF) mixing digital-to-analog converter (DAC) apparatus includes a load network, a first set of resistive DAC driver circuits and a first mixing core. The first mixing core can receive first RF input signals from the first set of resistive DAC driver circuits and can provide a first mixed signal to the load network. The first mixing core includes a first input differential pair coupled to two first cross-coupled differential pairs. The first input differential pair can receive first RF input signals at respective first input nodes. Each of the two first cross-coupled differential pairs can receive first positive and negative local oscillator (LO) signals at corresponding first input nodes. The first mixing core can mix the first RF input signals with the first positive and negative LO signals.

A headset system comprising a headset, which headset comprises at least a first earphone, a D/A converter, a first cable and a first connector. The headset system further comprises a control box, which control box comprises a second connecter, which is adapted to be connected to the first connector, and a third connector which is adapted to be connected to a fourth connector of a computing device. The control box comprises a user interface. The D/A converter is arranged at the headset and the control box is adapted to send control signals via the first cable to the headset, when the user interface is activated by a user.