A method for simulating and optimizing a digital to analog converter is disclosed. The method may include receiving a plurality of digital words. The method may also include determining an effective number of bits, a respective amplitude and a first amplitude correction amount for each digital word. Further, the first amplitude correction amount may be applied to each respective amplitude to generate respective first corrected amplitudes. A timing uncertainty may be determined which may be used to determine a second amplitude correction for each digital word. The second amplitude correction may be applied to each of the respective first corrected amplitudes to generate respective second corrected amplitudes. Next, a representation of an analog signal may be generated based in part on the second corrected amplitudes. Finally, a filter may be applied to the representation of the analog signal and then the representation of the analog signal is outputted.

Certain aspects of the present disclosure generally relate to a programmable multi-mode digital-to-analog converter (DAC) for generating a frequency-modulated signal. For example, certain aspects provide a circuit for sweeping a frequency of an output signal. The circuit generally includes a DAC having an input coupled to an input path of the circuit and an output coupled to an output path of the circuit, a first mixer selectively incorporated in the input path coupled to the input of the DAC, and a second mixer selectively incorporated in the output path coupled to the output of the DAC.

Due to strong needs to reduce the dimensions and the cost of the RF filters and to reduce the number of filters required in an mobile handsets and wireless system covering numbers of operation bands, tunable RF filters which can cover as many bands or frequency ranges as possible are needed so that the number of filters can be reduced in the mobile handsets and wireless systems. The present invention provides tunable surface acoustic wave (SAW) IDT structures with the resonant frequency of the acoustic wave to be excited and to be transmitted tuned by digital to analog converters (DACs). The DAC converts an input digital signal to an output DC voltage and provide DC bias voltages to the SAW IDTs through integrated thin film biasing resistors. The polarity and the value of the output DC voltage are controlled by the input digital signal to achieve selection and tuning of the resonant frequency of the SAW IDTs.

Due to strong needs to reduce the dimensions and the cost of the RF filters and to reduce the number of filters required in an mobile handsets and wireless system covering numbers of operation bands, tunable RF filters which can cover as many bands or frequency ranges as possible are needed so that the number of filters can be reduced in the mobile handsets and wireless systems. The present invention provides tunable surface acoustic wave (SAW) IDT structures with the resonant frequency of the acoustic wave to be excited and to be transmitted tuned by digital to analog converters (DACs). The DAC converts an input digital signal to an output DC voltage and provide DC bias voltages to the SAW IDTs through integrated thin film biasing resistors. The polarity and the value of the output DC voltage are controlled by the input digital signal to achieve selection and tuning of the resonant frequency of the SAW IDTs.

The present invention provides a calibration method applied to a DAC, wherein the calibration method includes the steps of: generating a first digital input signal to the DAC to generate a first analog signal; using an ADC to generate a first digital output signal according to the first analog signal; generating a second digital input signal to the DAC to generate a second analog signal; swapping a polarity of the second analog signal to generate a swapped signal; using the ADC to generate a second digital output signal according to the swapped signal; and generating a digital calibration signal according to the first digital output signal and the second digital output signal, to control a calibration circuit to generate an analog calibration signal or to determine a polarity direction of a DC offset that is to be calibrated.

Described herein is a device, system and method for digital-to-analogue conversion. One embodiment provides a digital-to-analogue converter device including: a) a first input configured to receive a digital signal to be converted; b) a second input configured to receive a digital dither signal, the digital dither signal having a predefined amplitude; c) a signal combining module that is configured to combine the digital dither signal with the digital signal in the digital domain to define a combined digital signal; and d) a digital-to-analogue converter module that is configured to process the combined digital signal and to output an analogue signal that is an analogue representation of the combined digital signal. The digital-to-analogue converter module has a predefined output amplitude range. The predefined amplitude of the dither signal is at least 1% of the predefined output amplitude range.

A sensing circuit includes a signal source circuit and a transient circuit. The signal source circuit provides a signal to the sensor via a conductor. When the sensor is exposed to a condition and is receiving the signal, an electrical characteristic of the sensor affects the signal, which is interpreted by the signal source circuit. When the sensing circuit is in a noisy environment, transient noise couples with the signal to produce a noisy signal. The transient circuit compares the noisy signal with a representation of the noisy signal. When the noisy signal compares unfavorably with the representation of the noisy signal, the transient circuit supplies a compensation signal to the conductor. The level of the compensation signal corresponds to a level at which the noisy signal compares unfavorably with the representation of the noisy signal.

A digitally-controlled power amplifier (DPA) includes a radio frequency digital-to-analog converter (RF-DAC) constructed from nonlinearly weighted PA segments, a multiphase RF drive signal generator that drives the PA segments, and overdrive voltage control circuitry. The nonlinear weighting of the PA segments intrinsically compensates for amplitude-code-word dependent amplitude distortion (ACW-AM distortion) involved in the operation of the RF-DAC and the multiphase RF drive signal generator facilitates ACW-dependent phase distortion (ACW-PM distortion) reduction, thus obviating the need for complicated and efficiency-degrading digital predistortion. The overdrive voltage control circuitry is used to fine tune the RF output of the DPA and compensate for other non-idealities and external influences such as process, voltage, temperature (PVT), frequency and/or load impedance variations.

A digitally-controlled power amplifier (DPA) includes a radio frequency digital-to-analog converter (RF-DAC) constructed from nonlinearly weighted PA segments, a multiphase RF drive signal generator that drives the PA segments, and overdrive voltage control circuitry. The nonlinear weighting of the PA segments intrinsically compensates for amplitude-code-word dependent amplitude distortion (ACW-AM distortion) involved in the operation of the RF-DAC and the multiphase RF drive signal generator facilitates ACW-dependent phase distortion (ACW-PM distortion) reduction, thus obviating the need for complicated and efficiency-degrading digital predistortion. The overdrive voltage control circuitry is used to fine tune the RF output of the DPA and compensate for other non-idealities and external influences such as process, voltage, temperature (PVT), frequency and/or load impedance variations.

A DA converter to reduce second-order harmonic distortion more precisely with convenient configurations. A DA converter including: a DA converting unit to input reference voltage and a digital value and output an analog signal according to the digital value based on the reference voltage; and a superimposing unit to superimpose, on the reference voltage, a superimposing signal based on the analog signal that is output from the DA converting unit, and a DA converting method are provided. The DA converter may further include a setting input unit to input setting regarding at least one of a superimposing amount and a sign of an analog signal to be included in the superimposing signal. Also, an adjusting apparatus and an adjusting method to adjust the DA converter are provided.