Method and system for an analog-to-digital converter with near-constant common mode voltage

A method for communication, the method comprising:

• in an analog-to-digital converter (ADC) comprising a first sampling switch on a first input line to the ADC, a second sampling switch on a second input line to the ADC, N switched capacitor pairs and M single switched capacitors on said first input line, and N switched capacitor pairs and M single switched capacitors on said second input line:
• sampling an input voltage by closing the first and second sampling switches;
• opening the first and second sampling switches and comparing voltage levels between the input lines;
• iteratively switching the switched capacitor pairs between a reference voltage (Vref) and ground based on the compared voltage levels;
• and
• iteratively switching the single switched capacitors between ground and voltages that are a fraction of Vref.

A system for communication, the system comprising:

• one or more circuits comprising an analog-to-digital converter (ADC) comprising a first sampling switch on a first input line to the ADC, a second sampling switch on a second input line to the ADC, N switched capacitor pairs and M single switched capacitors on said first input line, and N switched capacitor pairs and M single switched capacitors on said second input line said one or more circuits being operable to:
• sample an input voltage by closing the first and second sampling switches;
• open the first and second sampling switches and compare voltage levels between the input lines;
• iteratively switch the switched capacitor pairs between a reference voltage (Vref) and ground based on the compared voltage levels;
• and
• iteratively switch the single switched capacitors between ground and voltages that are a fraction of Vref.

A system for communication, the system comprising:

• one or more circuits comprising an analog-to-digital converter (ADC) comprising a first sampling switch on a first input lines to the ADC, a second sampling switch on a second input line to the ADC, a comparator, N switched capacitor pairs and M single switched capacitors on said first input line, and N switched capacitor pairs and M single switched capacitors on said second input line, said one or more circuits being operable to:
• sample an input voltage by closing the first and second sampling switches;
• open the first and second sampling switches and compare voltage levels between the input lines utilizing the comparator;
• iteratively switch the switched capacitor pairs between a reference voltage (Vref) and ground and compare voltage levels between the first and second input lines utilizing the comparator;
• and
• iteratively switch the single switched capacitors between ground and voltages that are a fraction of Vref and compare voltage levels between the first and second input lines utilizing the comparator.