You can design a circuit to increase or decrease output current at the output stage of comparator step by step till the offset is cancelled. Then the circuit burned some trimming cell bits to record the result.
chopping or SC are very wide used methods in offset cancellation ,and both of the two metods are dynamic .Is there any other method in offset cancellation? Now i am trying an offset cancellation method without capacitor. I tried several methods but they were very unstable.