Disclosed is an integrated circuit, which includes a DTC block including DTCs, receiving a first reference signal and a first division signal, and outputting a second reference signal and a second division signal based on the first reference signal, the first division signal, and control codes, a TDC comparing phases of the second reference signal and the second division signal and outputting a comparison signal, a digital loop filter filtering the comparison signal, an oscillator generating an output signal based on the filtered comparison signal, a delta-sigma modulator outputting a first signal and a quantized noise signal based on first and second division ratio signals, a divider dividing a frequency of the output signal based on the first signal and outputting the first division signal, and a probability modulator generating the control codes based on the quantized noise signal. Probability density functions of the control codes are time-invariant.

A sigma-delta modulator includes an N-bit quantization circuit that generates a stream of N-bit code words and a feedback signal path with an N-bit DAC circuit, having a non-ideal operation due to mismatch error, that converts the stream of N-bit code words to generate a feedback signal. A digital DAC copy circuit provides a digital replication of the N-bit DAC circuit. The digital replication accounts for the non-ideal operation of the N-bit DAC circuit 126 due to mismatch error, and converts the stream of N-bit code words to generate a stream of P-bit code words, where P>N, that are functionally equivalent to the feedback signal output from the N-bit DAC circuit.

A ring oscillator-based analog-to-digital converter (ADC). The ring oscillator-based ADC includes a ring oscillator and a transition detector. The ring oscillator may include a set of inverters coupled in a ring wherein an output of an inverter is coupled to an input of a successive inverter in the ring. The transition detector is configured to detect transitions of outputs of the inverters by comparing outputs of two separate inverters at two consecutive time instances. The transition detector may include two sets of registers configured to store outputs of the set of inverters at two consecutive time instances, respectively, and a set of comparators configured to compare the outputs stored in the two sets of registers. Each comparator may be configured to compare an output of one inverter at a first time instance and an output of another inverter at a second time instance.

A sigma-delta analog-to-digital converter includes: a subtractor for subtracting a feedback signal from an analog input signal; a loop filter for processing the output signal from the subtractor to generate a filtered signal; a signal comparing circuit for selectively operating in an offset detection mode or a signal comparison mode, wherein the signal comparing circuit generates an error signal irrelevant to the relative magnitude between the filtered signal and a reference signal in the offset detection mode, and generates a comparison signal corresponding to the relative magnitude between the filtered signal and the reference signal in the signal comparison mode; an offset calibration control circuit for calibrating the offset of the signal comparing circuit and for controlling the signal comparing circuit to alternately switch between the offset detection mode and the signal comparison mode; and a digital-to-analog converter for generating the feedback signal according to the comparison signal.

One example method of operation may include one or more of identifying a calling device number of a calling device, matching the calling device number with one or more of a plurality of enhanced call content profiles, selecting, based on a call identifier, one of the enhanced call content profiles comprising enhanced call content intended for one or more call recipient device numbers, and forwarding the enhanced call content associated with the selected enhanced call content profile to one of the call recipient devices.

The present invention provides an ADC for receiving at least an input signal to generate a digital output signal, wherein the ADC includes an input terminal and a plurality of output terminals, the input terminal is arranged to receive the input signal, and each of the output terminals is configured to output one bit of the digital output signal. The ADC is controlled to operate in a normal mode or a low power mode, and when the ADC operates in the normal mode, all of the output terminals are enabled to output the bits to form the digital output signal; and when the ADC operates in the low power mode, only a portion of the output terminals are enabled to output the bits to form the digital output signal.

A second-order modulator includes: a two-stage integrator; a first arithmetic operation circuit; and a second arithmetic operation circuit. The two-stage integrator includes a plurality of adder arrays, each of which includes a plurality of adders. The plurality of adder arrays includes first to fourth adder arrays. An output of a last stage of the second adder array is fed back as an input of a first stage of the first adder array. An output of a last stage of the fourth adder array is fed back as an input of a first stage of the third adder array. A sum bit string obtained in the first adder array is input to the third adder array. A sum bit string obtained in the second adder array is input to the fourth adder array.

A high-speed comparator circuit is provided. The circuit includes an amplifier portion, a latch portion, and a negative capacitance portion. The amplifier portion includes an input coupled to receive an analog signal and an output. The latch portion is coupled to the amplifier portion. The latch portion is configured to provide at the output a digital value based on the analog signal. The negative capacitance portion is coupled to the output. The negative capacitance portion is configured to cancel parasitic capacitance coupled at the first output.

A ring oscillator-based analog-to-digital converter (ADC). The ring oscillator-based ADC includes a ring oscillator and a transition detector. The ring oscillator may include a set of inverters coupled in a ring wherein an output of an inverter is coupled to an input of a successive inverter in the ring. The transition detector is configured to detect transitions of outputs of the inverters by comparing outputs of two separate inverters at two consecutive time instances. The transition detector may include two sets of registers configured to store outputs of the set of inverters at two consecutive time instances, respectively, and a set of comparators configured to compare the outputs stored in the two sets of registers. Each comparator may be configured to compare an output of one inverter at a first time instance and an output of another inverter at a second time instance.

The present invention provides a delta-sigma modulator and associated signal processing method, wherein the signal processing method includes: generating a first difference signal according to a difference between an input signal and a first feedback signal; filtering the first difference signal to generate a filtered signal; generating a second difference signal according to a difference between the filtered signal and a second feedback signal; quantizing the second difference signal to generate an output signal; using a first DAC to generate the first feedback signal according to the output signal; using a second DAC to generate a first analog signal according to the output signal; delaying the output signal to generate a first delayed output signal; using a third DAC to generate a second analog signal according to the first delayed output signal; and generating the second feedback signal according to the first analog signal and the second analog signal.