Low-voltage comparator-based switched-capacitor networks

A switched-capacitor network for performing an analog circuit function comprising:

• a switched-capacitor network having an input terminal to receive an input voltage and a plurality of switches, each switch having a respective threshold voltage and in communication with one of a high-limit voltage, a low-limit voltage, and electrical ground;
• a comparator having an output terminal, a first input terminal, and a second input terminal, the first input terminal in communication with the switched-capacitor network and configured to receive a node voltage therefrom during a first phase for sampling of the input voltage, the second input terminal configured to receive one of a high-limit voltage and a low-limit voltage;
• a voltage-offset network in communication with the first input terminal, the voltage-offset network providing a voltage shift at the first input terminal setting an input reference level at a mid-level voltage with respect to the high-limit and low-limit voltages;
• a sampling capacitor coupled between the output terminal and one of the high-limit and low-limit voltages;
• and
• a sampling switch coupled between the sampling capacitor and the one of the high-limit and low-limit voltages, the sampling switch having a control input coupled to the comparator output terminal.

A method for performing an analog circuit function in a circuit comprising a comparator in communication with a switched-capacitance network, comprising:

• sampling by the switched-capacitance network an input voltage during a first phase, the switched-capacitance network having a plurality of switches, each having a respective threshold voltage and in communication with one of a high-limit voltage, a low-limit voltage, and electrical ground;
• applying a voltage present at a node within the switched-capacitance network to a first comparator input terminal;
• applying one of the high-limit voltage and the low-limit voltage to a second comparator input terminal;
• and
• applying a voltage shift to the first comparator input terminal setting an input reference level at a mid-level voltage with respect to the high-limit voltage and the low-limit voltage.

A switched-capacitor network for performing an analog circuit function comprising:

• means for sampling by the switched-capacitance network an input voltage during a first phase, the switched-capacitance network having a plurality of switches, each switch having a respective threshold voltage and in communication with one of a high-limit voltage, a low-limit voltage, and electrical ground;
• means for applying a voltage present at a node within the switched-capacitance network to a first comparator input terminal;
• means for applying one of a high-limit voltage and a low-limit voltage to a second comparator input terminal;
• and
• means for applying a voltage shift to the first comparator input terminal to set an input reference level at a mid-level voltage with respect to the high-limit and low-limit voltages.