Pipelined Analog-To-Digital Converter

A pipelined analog-to-digital converter (ADC), comprising:

• a first sub ADC;
• and
• a second sub ADC configured to receive, as an input, an analog residue generated by the first sub ADC;
• wherein the first sub ADC is configured to operate in:
• a first conversion phase in which it generates a digital output of the first sub ADC;
• and
• a second conversion phase in which it generates the analog residue;
• wherein the first sub ADC comprises a reference-voltage generator circuit:
• configured to generate a reference voltage of the first sub ADC;
• having a first mode of operation;
• having a second mode of operation in which a noise power of the reference voltage is less than in the first mode of operation;
• and
• configured to operate in its first mode of operation in the first conversion phase and in its second mode of operation in the second conversion phase.

A method of operating a pipelined analog-to-digital converter (ADC);

• the pipelined ADC comprising a first sub ADC and a second sub ADC;
• wherein the second sub ADC is configured to receive, as an input, an analog residue generated by the first sub ADC;
• wherein the first sub ADC is configured to operate in 1) a first conversion phase in which it generates a digital output of the first sub ADC, and 2) a second conversion phase in which it generates the analog residue;
• , first sub ADC comprises a reference-voltage generator circuit configured to generate a reference voltage of the first sub ADC;
• wherein the reference-voltage generator circuit has a first mode of operation and a second mode of operation;
• wherein a noise power of the reference voltage is less in the second mode of operation than in the first mode of operation;
• the method comprising:
• operating the reference-voltage generator circuit in its first mode of operation in the first conversion phase;
• and
• operating the reference-voltage generator circuit in its second mode of operation in the second conversion phase.

An electronic apparatus, comprising:

• a pipelined ADC, the pipelined ADC comprising:
• a first sub ADC;
• and
• a second sub ADC configured to receive, as an input, an analog residue generated by the first sub ADC;
• wherein the first sub ADC is configured to operate in:
• a first conversion phase in which it generates a digital output of the first sub ADC;
• and
• a second conversion phase in which it generates the analog residue;
• wherein the first sub ADC comprises a reference-voltage generator circuit:
• configured to generate a reference voltage of the first sub ADC;
• having a first mode of operation;
• having a second mode of operation in which a noise power of the reference voltage is less than in the first mode of operation;
• and
• configured to operate in its first mode of operation in the first conversion phase and in its second mode of operation in the second conversion phase.