Apparatus and method for an analog to digital converter

A method comprising:

• configuring an amplifier to operate in an offset cancellation phase to generate a first offset voltage at a first output of the amplifier and a second offset voltage at a second output of the amplifier, and store the first offset voltage and the second offset voltage at a first storage element and a second storage element respectively, wherein the first storage element is coupled to the first output of the amplifier through a first auxiliary switch, and the second storage element is coupled to the second output of the amplifier through a second auxiliary switch;
• configuring the amplifier to operate in a reset phase through turning on a first reset switch coupled between the first output and the second output of the amplifier;
• and
• configuring the amplifier to operate in an amplification phase, wherein in the amplification phase, a first offset-cancellation voltage and a second offset-cancellation voltage are fed into the first output and the second output of the amplifier, respectively.

An apparatus comprising:

• a load pair including a first transistor and a second transistor;
• a common mode feedback circuit comprising a first common mode feedback transistor and a second common mode feedback transistor, wherein:
• a drain of the first common mode feedback transistor is coupled to a source of the first transistor, and a gate of the first common mode feedback transistor is coupled to a drain of the first transistor;
• and
• a drain of the second common mode feedback transistor is coupled to a source of the second transistor, and a gate of the second common mode feedback transistor is coupled to a drain of the second transistor;
• and
• an offset cancellation stage coupled to outputs of the load pair.