Methods and apparatus to improve performance specifications of amplifiers

An amplifier comprising:

• input circuitry including:
• a main input pair having a first input, a first output, and a second output;
• an auxiliary input pair having a first input, a first output, and a second output, the first output of the auxiliary input pair coupled to the first output of the main input pair, and the second output of the auxiliary input pair coupled to the second output of the main input pair;
• current steering circuit;
• source follower circuitry comprising:
• a first transistor having a source coupled to the first input of the main input pair, and a gate configured to receive the smaller of a first signal or a second signal;
• and
• a second transistor having a gate and a drain, the drain of the second transistor coupled to the source of the first transistor;
• and
• a comparator having an output coupled to the gate of the second transistor, the output of the comparator further coupled to the first input of the main input pair and to the first input of the auxiliary input pair via the current steering circuit, the comparator configured to control operation of the main input pair and the auxiliary input pair;
• first stage circuitry having an input and an output, the input of the first stage circuitry coupled to the first and second outputs of the main input pair, and to the first and second outputs of the auxiliary input pair;
• and
• second stage circuitry having an input coupled to the output of the first stage circuitry.

A system comprising:

• a first amplifier stage having an input;
• a first input pair having a first input, and a first output, the first output coupled to the input of the first amplifier stage;
• a second input pair having a first input, and a first output;
• current steering circuitry having first and second inputs, and first and second outputs, the first output of the current steering circuitry coupled to the first input of the first input pair, and the second output of the current steering circuitry coupled to the first input of the second input pair;
• source follower circuitry having an input and an output, the output of the source follower circuitry coupled to the first input of the first input pair;
• and
• a comparator having an output coupled to the input of the source follower circuitry, wherein the source follower circuitry comprises:
• a first transistor having a source and a gate, the source of the first transistor coupled to the first input of the first input pair, and the gate of the first transistor configured to receive the smaller of a first signal or a second signal;
• and
• a second transistor having a gate and a drain, the gate of the second transistor coupled to the output of the comparator, and the drain of the second transistor coupled to the source of the first transistor.