Match & Noise
PIT E L
蒋苓利
2022-6-5
Devices for match:
电流镜(MOS、电阻)
用于分压的电阻(AD/DA)
用于电流比例设定的电阻
差分对
电压/电流基准源
用于运放加/减比例设置的电阻
……
Rules for match:
Place devices close to each other
Keep the device in the same orientation
Device in the same size
Choose a middle value for root component
Interdigitating device
Common centroid & Symmetry
Dummy device for over-etching
Match the parasitic parameter
Rules for match
Place devices close to each other
Upper
Limit
y1
y2
Lower
Limit
x1 x2
x,y
x- x , y+ y
x+ x , y- y
• The closer between the two
components, the more similar
for these two components.
• In the small region, the
characteristic curve can be
viewed as “linear”.
• The distance between
the devices should be the
same.
Rules for match
Keep the device in the same orientation
标准尺寸: 20/5
横向放置 20/4
Rules for match
Device in the same size
Two in series
Two in parallel Four in parallel
Rules for match
Choose a middle value for root component
Match for R1=4k R2=16k
Which one is better?
Rules for match
Choose a middle value for root component
阻值居中
长度、宽度在精度范围内
所占面积最小
经验值(0.5um):
宽度:
最窄2um,仅用于无需任何阻值精度要求的大电阻
普通匹配3~4um
高精度匹配5~6um
长度:
有精度要求者,方块值最好在6个以上
50~60um左右为佳,太长易断