Multi-comparison analog-to-digital converters using the interpolation principle

Multi-comparison interpolation comparator comprising:

• at least two auto-zeroing comparators, each auto-zero comparator including a first stage comprising a capacitor coupled through a first switch to a reference voltage, and coupled through a second switch to a voltage to be compared to said reference voltage,
• said capacitor being coupled to a first inverter whose terminals are connected through a third switch,
• said first Inverter being coupled to a second stage comprising a second autozeroed inverter and
• a median comparator comprising only a second stage connected to the outputs of the inverters of the first stages of two adjacent auto-zeroing comparators, said second stage of said median comparator comprising:
• a first pair of transistors, the gates of which are controlled respectively by the outputs of the first inverters of the adjacent auto-zeroing comparators;
• a second pair of transistors which combined with the first pair of transistors perform the function of an inverter;
• a third pair of transistors whose sources and drains are connected to the supply voltage in order to perform the function of a capacitor, the gates of said third pair of transistors being connected to the gates of said second pair of transistors;
• a switch connecting the output of the inverter formed by said first and second pairs of transistors to the gates of the second and third pairs of transistors;
• and
• a switch connecting the gates of said second and third pairs of transistors to a supply voltage.