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) P6 ^9 z8 e5 F9 j* @/ j" R这边我用一个简单的放大电路来演示.网表文件:$ j3 M6 [- m0 C( @+ ~
*File: OPAC.SP*1 m- _; |/ |+ ?: A# W( g+ m+ c
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.OPTION POST nomod2 s, R) D* n9 N, R1 l
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m1 10 2 6 7 mp w=40u l=2u8 M- s( U' h5 a
m2 4 3 6 7 mp w=40u l=2u6 f2 V) O: s: @, T5 L. q& x& G
m3 9 10 10 9 mn w=3u l=3u
4 l8 h6 |; I- h0 [; p% f3 n0 Sm4 4 10 9 9 mn w=3u l=3u. b- p0 `" c. x. [6 I# E$ u# z; c# n
m5 6 8 7 7 mp w=8u l=2u9 e0 ]# M: l4 c
m6 1 8 7 7 mp w=60u l=2u
3 s9 o8 K w# wm7 1 4 9 9 mn w=30u l=2u
& N5 h+ A% R+ s$ W( |( nc1 4 1 cap
6 x$ h$ {0 \1 N# z$ N% cc2 1 0 10pf8 \3 y3 x+ I1 V& ~! Q
vdd 7 0 5
! c0 q4 @! i8 E# gvss 9 0 -5: E2 [% r# ~- R# \0 F, s9 I4 ^
v1 2 0 0
2 \1 l3 j; E$ U' Hv2 3 0 0 ac 1
9 Y0 ?' O# {5 b' j6 tv3 7 8 2.2
" D) V/ j# I/ j7 c% |( l# k% _/ N4 B2 g.model mn nmos (level=2 vto=1 kp=35u lambda=0.02)! Q# N" }- f8 Y) k; P3 K
.model mp pmos (level=2 vto=-1 kp=12u lambda=0.02)5 f' o% h" J7 p- p1 F
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.param cap=8pf9 _4 ~( f$ s, l$ K
.ac dec 5 1 10meg, k9 s, J% {" M; I6 E
.noise V(1) V2 104 A: [1 Z6 a! Z- u
.probe ac vdb(1) vp(1) inoise onoise innoise outnoise- |; V9 ~' z& y3 d
.op
) q( l, J0 Q+ E7 m/ L.end
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" Y: J; o! A' e4 g! `( o' R1 h该放大电路输入信号为v2,输出端口为1,此时输出端接电容.( X) U1 l y# j) C/ y, Y
根据HSPICE手册,我选择了.noise语句来分析该放大路的噪声.仿真得到的结果我不是很能理解,如在.lis文件中会有结果:$ _( c( I9 ^* m
**** total output noise voltage = 933.5783a sq v/hz
: ] q# @2 M+ S5 B% M+ i! _, k; p% V transfer function value: = 30.5545n v/rt hz - S4 i' j p% R
v(1)/v2 = 1.5697
$ a# L$ o6 X7 N$ z7 c, o equivalent input noise at v2 = 19.4657n /rt hz 8 I6 l7 a# {: [! f8 h3 s2 l1 D/ J
/ o0 j; p; E# E, N! F8 z **** the results of the sqrt of integral (v**2 / freq)3 Y* ?) y- _$ K
from fstart upto 1.0000x hz. using more freq points9 v4 y) m% F4 {, N x2 u% T
results in more accurate total noise values.0 ?' G" j3 L# j% N5 j$ X
& \( L. ?. F+ G7 D **** total output noise voltage = 2.3566m volts
5 P, k5 j! k, {" B8 X **** total equivalent input noise = 19.1806u
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2 S- z( Z& r5 A5 r/ P# @) t: E以上各种数据都表示什么含义啊?
3 D- n: W9 ?, c$ x在仿真结果文件(.ac0)文件中还有 inoise /onoise /innoise /outnoise等结果,又是什么含义?6 R8 y" h8 l9 U: l( Q
而且我比较关注电路的噪声系数NF, 而NF可以用(total output noise voltage)/(total equivalent input noise)来表示吗?, f. D1 R( A; l5 w r# h. X" @, c
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