Abstract:
A novel and useful LC-tank digitally controlled oscillator (DCO) incorporating a split transformer configuration. The LC-tank oscillator exhibits a significant reduction in area such that it is comparable in size to conventional ring oscillators (ROs) while still retaining its salient features of excellent phase noise and low sensitivity to supply variations. The oscillator incorporates an ultra-compact split transformer topology that is less susceptible to common-mode electromagnetic interference than regular high-Q LC tanks which is highly desirable in SoC environments. The oscillator, together with a novel dc-coupled buffer, can be incorporated within a wide range of circuit applications, including clock generators and an all-digital phase-locked loop (ADPLL) intended for wireline applications.
Abstract:
An analog-to-digital converter (ADC) system and method. The ADC system in accord with one embodiment includes a sampling digital-to-analog converter configured to sample a combination of an analog signal value and an analog dither value, and a control circuit comprising a mismatch-shaping encoder. The control circuit is configured to sequentially apply a plurality of digital codes to the sampling digital-to-analog converter during an analog-to-digital conversion operation to derive a digital code representing the combination of the analog signal value and the analog dither value. Several embodiments are presented.
Abstract:
There is described a time-to-digital conversion scheme using an arrangement of delay elements based Time-to-Digital Converter, TDC (20), wherein dithering is built in the digital domain and introduced in the analog domain as a modulation of a supply voltage (TDC-supply) supplying delay elements of the TDC, each having a propagation delay which exhibits a dependency to their supply voltage.
Abstract:
A semiconductor communication device reduces influence of noise that is produced by applying a dither signal. The semiconductor communication device includes a Delta-Sigma analog-to-digital converter that converts input analog signals to digital signals, a power detecting unit that detects signal power of the digital signals, a gain control unit that changes a gain setting of analog signals to be input to the Delta-Sigma analog-to-digital converter depending on the signal power of the digital signals, and a dither signal control unit that causes the Delta-Sigma analog-to-digital converter to selectively add the dither signal when the gain setting changes.
Abstract:
An analog-to-digital converter (ADC) system and method. The ADC system in accord with one embodiment includes a sampling digital-to-analog converter configured to sample a combination of an analog signal value and an analog dither value, and a control circuit comprising a mismatch-shaping encoder. The control circuit is configured to sequentially apply a plurality of digital codes to the sampling digital-to-analog converter during an analog-to-digital conversion operation to derive a digital code representing the combination of the analog signal value and the analog dither value. Several embodiments are presented.
Abstract:
Techniques and devices provide analog-to-digital conversion at two or more signal frequencies or frequency bands and can be used to construct multi-mode analog-to-digital converters in various circuits, including receivers and transceivers for wireless communications and radio broadcast environments. Adjustable analog-to-digital converters based on the described techniques can be configured to adjust circuit parameters to adapt the technical specifications of different input signals at different signal frequencies or frequency bands, such as FM, HD-radio, and DAB radio signals in radio receiver applications.
Abstract:
An analog-to-digital (A/D) converter circuit arranged for receiving an analog input signal and for outputting a digital representation of said analog input signal is described. The A/D converter circuit includes: a first converter stage configured for receiving the analog input signal and for generating a first set of conversion bits, a first completion signal and a residual analog output signal representing the difference between the analog input signal and a signal represented by said first set of conversion bits, a second converter stage comprising a clock generation circuit arranged for receiving the first completion signal and for generating a clock signal, a plurality of comparators each being configured for receiving the residual analog output signal and a common reference voltage, said plurality of comparators arranged for being activated by the clock signal and for outputting a plurality of comparator decisions, a digital processing stage configured for receiving the plurality of comparator decisions and for generating a second set of conversion bits, means for generating the digital representation of the analog input signal by combining the first and second set of conversion bits.
Abstract:
A low-cost charge injection mechanism may enable oversampling to be used on low frequency signals by injecting dither noise into the ADC input. The dither noise can reduce the quantization noise allowing even direct current (DC) signals to be oversampled correctly. A low-cost charge injection mechanism can also be used to improve the ENOB by characterizing the ADC and digitally correcting the converted signal for non-linearity errors such as INL. Reducing INL errors may also allow a higher degree of oversampling to be used to further improve the ENOB.
Abstract:
A method of analog to digital voltage conversion including: generating a quadratic signal based on an analog time varying reference signal; generating a ramp signal based on the quadratic signal; and converting an analog input voltage to a digital output value based on a time duration determined by a comparison of the analog input voltage with the ramp signal.
Abstract:
An AD conversion apparatus includes a shift signal generating portion configured to generate n shift signals (n is a natural number greater than one) of which amplitudes are different from each other; a shift signal controlling portion configured to control the shift signal generating portion; a compounding portion configured to compound input analog signal and the n shift signals sequentially into n first signals; an AD converting portion configured to execute AD conversion to convert the n first signals into n second signals; and a signal processing portion configured to calculate an average of the n second signals to generate output digital signal.