Analog-to-digital converter, method for driving the same, image sensor, imaging apparatus, and battery monitoring system

An A/D converter, comprising:

• a first integrator that integrates a signal obtained by adding a first feedback signal and a fourth feedback signal to an analog input signal, to generate a first output signal;
• a first quantizer that converts the first output signal into a first digital signal;
• a first D/A converter that converts the first digital signal into a first analog signal;
• a second integrator that integrates a signal obtained by adding the first analog signal and a second feedback signal to the first output signal, to generate a second output signal;
• a second quantizer that converts the second output signal into a second digital signal;
• a second D/A converter that converts the second digital signal into a second analog signal;
• a third integrator that integrates a signal obtained by adding the second analog signal and a third feedback signal to the second output signal, to generate a third output signal;
• a third quantizer that converts the third output signal into a third digital signal;
• and
• a third D/A converter that converts the third digital signal into a third analog signal,
• wherein the first feedback signal is the first analog signal,
• the second feedback signal is the second analog signal,
• the third feedback signal is the second analog signal, and
• the fourth feedback signal is the third analog signal.

An A/D converter comprising delta-sigma modulators at a plurality of stages,

• each of the delta-sigma modulators including:
• an integrator that integrates a signal obtained by adding a plurality of input signals and a feedback signal, to generate an output signal;
• a quantizer that quantizes the output signal into a digital signal;
• and a D/A converter that converts the digital signal into the feedback signal that is an analog signal,
• wherein among the delta-sigma modulators, a delta-sigma modulator at a last one of the stages outputs the feedback signal to a delta-sigma modulator at a first one of the stages,
• the input signals of the delta-sigma modulator at the first one of the stages include an analog input signal and the feedback signal from the delta-sigma modulator at the last one of the stages, and
• the input signals of delta-sigma modulators at second and subsequent ones of the stages include a signal output from the integrator of each of delta-sigma modulators that precede the delta-sigma modulators at the second and subsequent ones of the stages, and the feedback signal from each of the delta-sigma modulators that precede the delta-sigma modulators at the second and subsequent ones of the stages.

A method for driving an A/D converter, the method comprising:

• integrating a signal obtained by adding a first feedback signal and a third feedback signal to an analog input signal, to generate a first output signal;
• converting the first output signal into a first digital signal;
• converting the first digital signal into a first analog signal;
• integrating a signal obtained by adding the first analog signal and a second feedback signal to the first output signal, to generate a second output signal;
• converting the second output signal into a second digital signal;
• and
• converting the second digital signal into a second analog signal,
• wherein the first feedback signal is the first analog signal,
• the second feedback signal is the second analog signal, and
• the third feedback signal is the second analog signal.

A method for driving an A/D converter, the method comprising:

• integrating a signal obtained by adding a first feedback signal and a fourth feedback signal to an analog input signal, to generate a first output signal;
• converting the first output signal into a first digital signal;
• converting the first digital signal into a first analog signal;
• integrating a signal obtained by adding the first analog signal and a second feedback signal to the first output signal, to generate a second output signal;
• converting the second output signal into a second digital signal;
• converting the second digital signal into a second analog signal;
• integrating a signal obtained by adding the second analog signal and a third feedback signal to the second output signal, to generate a third output signal;
• converting the third output signal into a third digital signal;
• and
• converting the third digital signal into a third analog signal,
• wherein the first feedback signal is the first analog signal,
• the second feedback signal is the second analog signal,
• the third feedback signal is the second analog signal, and
• the fourth feedback signal is the third analog signal.