An analog-to-digital converter (ADC) using an amplifier-based noise shaping circuit. The amplifier-based noise shaping circuit generates a noise shaping signal. A comparator of the ADC has a first input terminal coupled to an output terminal of a capacitive data acquisition converter that captures an analog input, a second input terminal receiving the noise shaping signal, and an output terminal for observation of the digital representation of the analog input. The amplifier-based noise shaping circuit uses an amplifier to amplify a residual voltage obtained from the capacitive data acquisition converter and provides a switched capacitor network between the amplifier and the comparator for sampling the amplified residual voltage and generating the noise shaping signal.

An A/D converter includes an analog input terminal, a successive approximation A/D converter connected to the analog input terminal, the successive approximation A/D converter for generating an upper conversion result at an upper conversion result terminal, the successive approximation A/D converter having an internal D/A converter generating an internal reference voltage at an internal reference voltage terminal, and a delta-sigma A/D converter connected to the analog input terminal and the internal reference voltage terminal, the delta-sigma A/D converter for generating a lower conversion result at a lower conversion result terminal.

An analog front end (AFE) system for substantially eliminating quantization error or noise can combine an input of an integrator circuit in the AFE system with an input of the digital-to-analog converter (DAC) circuit in the feedback loop of the AFE system. By combining the input of the integrator with the input of the DAC circuit in the feedback loop, the in-band quantization noise of the filter can be substantially eliminated, thereby improving measurement accuracy.

Each of a plurality of analog-to-digital (AD) converters configuring a column AD converter used in an image sensor comprises: an oversampling AD converter that receives an output voltage of a pixel unit; a recursive AD converter that receives an analog residual signal of the oversampling AD converter; and a counter that adds a digital signal output from the oversampling AD converter and a digital signal output from the recursive AD converter. The controller dynamically allocates the number of bits of the oversampling AD converter and the number of bits of the recursive AD converter, while maintaining the total number of bits of the oversampling AD converter and the recursive AD converter.

An analog-to-digital converter configured to convert an analog signal into a digital signal includes a first converter configured to receive an input signal of an analog type, compare the input signal with a plurality of reference signals, select one of the plurality of reference signals based on the comparison, and output an upper bit that is a portion of the digital signal based on the selected reference signal, a second converter configured to perform an oversampling operation n times based on a residue signal indicating a difference between an upper analog signal corresponding to the upper bit value and the input signal and output an intermediate bit value of the digital signal corresponding to the first to n-th oversampling signals generated respectively during the oversampling operations performed n times, and a third converter configured to output a lower bit value of the digital signal corresponding to the n-th oversampling signal.

An analog-to-digital converter (ADC) using an amplifier-based noise shaping circuit. The amplifier-based noise shaping circuit generates a noise shaping signal. A comparator of the ADC has a first input terminal coupled to an output terminal of a capacitive data acquisition converter that captures an analog input, a second input terminal receiving the noise shaping signal, and an output terminal for observation of the digital representation of the analog input. The amplifier-based noise shaping circuit uses an amplifier to amplify a residual voltage obtained from the capacitive data acquisition converter and provides a switched capacitor network between the amplifier and the comparator for sampling the amplified residual voltage and generating the noise shaping signal.

A wide bandwidth radio system designed to adapt to various global radio standards and, more particularly, to a radio receiver composed of a demodulator operative to work in a delta sigma mode and a Nyquist mode, and wherein a filter and feedback loop may utilized in response to the modulation mode of an RF signal.

A device includes a first conversion stage, a second conversion stage, and a first filter circuit. The first conversion stage is configured to perform a Delta-Sigma modulation based on an input signal, in order to generate a first quantized signal and a first residual signal. The second conversion stage is configured to perform a pipelined successive approximation algorithm in response to the first residual signal, in order to generate a second quantized signal. The first filter circuit is configured to perform a decimation process based on the first quantized signal and the second quantized signal to generate a digital output signal.

Each of a plurality of analog-to-digital (AD) converters configuring a column AD converter used in an image sensor comprises: an oversampling AD converter that receives an output voltage of a pixel unit; a recursive AD converter that receives an analog residual signal of the oversampling AD converter; and a counter that adds a digital signal output from the oversampling AD converter and a digital signal output from the recursive AD converter. The controller dynamically allocates the number of bits of the oversampling AD converter and the number of bits of the recursive AD converter, while maintaining the total number of bits of the oversampling AD converter and the recursive AD converter.

Disclosed herein are systems and methods that describe a noise-shaping (NS) SAR architecture that can be simple, effective, and low power. In an aspect, a method includes the operation of receiving a first analog input; determining a first digital output based on the first analog input; obtaining a first quantization error for the first digital output; integrating the first quantization error; receiving a second analog input; and determining a second digital output based on the summation of the second analog input and the first integrated quantization error to perform noise-shaping.