Systems and methods are disclosed for a noise-shaping successive approximation register (SAR) analog-to-digital-converter (ADC) using Sampled Analog Technology (SAT) filter techniques for filter construction. A SAR ADC includes an SAR for receiving an analog input signal and outputting a digital decision, a digital-to-analog converter and logic circuitry for converting the digital decision of the SAR to a present analog residue for a present conversion cycle, a filter for processing a previous analog residue from a previous conversion cycle, and for feeding a processed previous analog residue back to the SAR, a summer for summing the processed previous analog residue from the filter and the present analog residue, and generating a summer output, and a comparator for comparing the summer output and a first reference signal and generating a comparator output. The filter includes a capacitor array for filtering the previous analog residue to generate the processed previous analog residue.

This disclosure describes techniques for transferring data from an analog-to-digital converter (ADC) to a host device. The techniques may determine whether an ADC is operating in a quiet conversion time period, and selectively deactivate a digital data output of the ADC when the ADC is operating in the quiet conversion time period. This may allow an ADC to transfer data during both the conversion and acquisition phases of the ADC (rather than just during the acquisition phase), thereby increasing the data throughput of the ADC for a given transfer clock speed. The techniques may further allow data to be transferred during the conversion phase of an ADC without requiring a host device to be aware of the quiet conversion time period requirements of the ADC. In this way, the data throughput of an ADC data transfer may be increased with relatively little additional complexity added to a host device.

A device for conversion of an analog signal into a digital signal includes a clock signal generator and a ramp generator configured for delivering a rising voltage ramp. A comparator is configured for comparing the value of the analog signal and the value of the voltage ramp and for generating a comparison signal taking a first logical value when the two values are equal. A signal generator is configured for generating a counter signal equal to the inverse of the clock signal if the comparison signal takes its first value while the clock signal is in the high state, or a counter signal equal to the clock signal if the clock signal is in the low state. A counter is configured for counting the number of edges of the counter signal.

The present disclosure relates to implementations of a method and a system for calibrating the system that includes analog-to-digital converters (ADCs). The method, performed on the system's corresponding components include, providing, from a signal generator, a first signal during a calibration mode. Parallel ADCs provide ADC outputs associated with the first signal. First parallel filters provide derivative signals associated with the ADC outputs. Second and third parallel filters provide first and second band-stop filtered signals associated with the ADC outputs and the derivative signals, respectively. The disclosure includes multiplying the first and the second band-stop filtered signals and selecting a portion of the multiplied signals that are accumulated for storage. The system incorporating these components performing these features is, accordingly, calibrated.

An amplifier circuit includes a sampling circuit and an amplifier connected to an output of the sampling circuit. A feedback capacitor is between an output terminal of the amplifier and an output terminal of the sampling circuit. A quantizer that includes a comparator is configured to quantize a voltage at the output terminal of the sampling circuit according to a comparison of a voltage at the output terminal of the sampling circuit to a voltage at the reference potential terminal of the comparator. The quantizer outputs a digital code according to the voltage comparison. A control circuit receives the digital code from the quantizer and stores the digital code in a register as a cancellation digital code. A digital-analog (D/A) converter outputs an analog signal in accordance with digital codes from the control circuit.

An optical data coding method includes at least steps of selecting a modulation scheme comprising an X-polarization constellation format having first and second amplitude rings with circular grids corresponding to predetermined phase angles and a Y-polarization constellation format having the first and second amplitude rings with the circular grids corresponding to the predetermined phase angles, arranging a first part of the symbol on a first circular grid of the first amplitude ring on the X-polarization constellation format, and arranging a second part of the symbol on a second circular grid of the second amplitude ring on the Y-polarization constellation format.

A current digital-to-analog converter (DAC) and an integrated circuit chip including the DAC are disclosed. The current DAC includes a switching circuit that includes a plurality of switches coupled to receive differential digital control signals and to provide first and second differential current outputs, a current source coupled to an upper rail and to a first node of the switching circuit, a first current sink coupled to a lower rail and to a second node of the switching circuit, and an interference cancellation circuit coupled to substantially prevent a tail capacitance current from flowing through the first and second differential current outputs.

The systems and methods discussed herein utilized a wireless or wired transceiver having a transmitter and a receiver. The transceiver is configured to reduce distortion contributions associated with echo cancelling. The transmitter provides a replica signal and a transmit signal. The replica signal and the transmit signal can be provided using a common switch.

An A/D conversion circuit includes a reference voltage source to generate a calibration voltage, a multiplexer to receive an analog signal and the calibration voltage, and output the analog signal selected in a normal mode and the calibration voltage selected in a calibration mode or a self-diagnosis mode, an A/D converter to convert an output signal from the multiplexer into a digital signal, a non-volatile memory to hold the digital signal and calibration data, a digital calibration part to calibrate the digital signal in case of inputting the analog signal to the A/D converter in the normal mode based on the calibration data, and a self-diagnosis circuit to diagnose the A/D converter based on the digital signal in case of inputting the calibration voltage to the A/D converter in the self-diagnosis mode, and the digital signal stored in the non-volatile memory.

Aspects of a method and system for a successive approximation analog-to-digital converter with dynamic search algorithms are provided. In some embodiments, a successive approximation analog-to-digital converter includes a digital-to-analog converter, a comparator, and a search and decode logic modules which cooperate to generate a digital output code representative of the analog input voltage based on a dynamic search algorithm. The dynamic search algorithms may alter a sequence of reference voltages used to successively approximate the analog input voltage based on one or more characteristics of the analog input voltage.