3 methods:
1. Chopper stabilization:
Advantage:
a. fully on-chip solution.
Disadvantage:
a. LP filter limits the amplifier's bandwidth.
2. Autozeroing:
Advantage:
a. fully on-chip ( discrete-time signal ) or almost fully on-chip ( continuous time )
Disadvantage:
a. Need large or external cap to store the offset ( continuous time )
3. Trim:
Advantage:
a. size is relative smaller than the others.
Disadvantage:
a. need extra trim procedure.