大家一般用什么方法消除DC offset

nesta · 发表于 2009-2-5 17:31:26

chopper在外界能够提供clock的情况下还是很容易实现的
输出需要低通滤波
可能需要注意的就是调制与解调之间最好有一点delay以抵消op自身信号传输的delay
不过对于dc来讲，这个delay也不太需要

ycj · 发表于 2009-2-5 20:09:52

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.