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这边我用一个简单的放大电路来演示.网表文件:. ]2 G, V3 r4 b: k5 x0 [: G
*File: OPAC.SP*+ z( s6 S/ b: o2 B0 I/ b% ?
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.OPTION POST nomod
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0 z2 c _. o0 j3 f) x- M8 i4 {; y+ xm1 10 2 6 7 mp w=40u l=2u& V* L/ ~# R, N' i+ y+ b5 U
m2 4 3 6 7 mp w=40u l=2u& k/ q+ f8 e6 {5 v% D- M3 ?: p; j
m3 9 10 10 9 mn w=3u l=3u
3 f$ P6 N4 v3 L, A. c2 rm4 4 10 9 9 mn w=3u l=3u
) E$ T0 N' r: C' ~2 Zm5 6 8 7 7 mp w=8u l=2u/ w3 H, V& z) u- V0 ?
m6 1 8 7 7 mp w=60u l=2u3 P. P9 d3 H s2 ]' `
m7 1 4 9 9 mn w=30u l=2u/ I3 |7 [$ U' _/ K; e e4 T
c1 4 1 cap. d0 _1 m3 a. t6 c
c2 1 0 10pf
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vss 9 0 -5
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. y2 J$ |% t$ ]: m y) W7 Kv2 3 0 0 ac 1& V+ s( Y- E3 @, M# F. k- X, a+ O
v3 7 8 2.24 L! {8 H) s0 u$ a" h- S; w4 o
.model mn nmos (level=2 vto=1 kp=35u lambda=0.02)
( N# T7 d+ I+ U; A1 n& m- U.model mp pmos (level=2 vto=-1 kp=12u lambda=0.02)
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8 R4 r/ [ \( k. n; l# [9 o- ].param cap=8pf2 s* @' \4 X% o
.ac dec 5 1 10meg
" m2 N; ^4 ?2 _/ I9 H4 u.noise V(1) V2 10, N1 i5 ^9 I! F. L
.probe ac vdb(1) vp(1) inoise onoise innoise outnoise, S9 b& e; L8 x& U h' D2 z5 @
.op
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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.
6 o2 H' {( X- B. e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:
" }" h3 h7 B+ ~ d7 M! t* ? **** total output noise voltage = 933.5783a sq v/hz8 M B4 r( g8 q, Z6 ^
transfer function value: = 30.5545n v/rt hz
3 S$ k7 w0 ^) r | v(1)/v2 = 1.5697 9 ^. h: }/ {* v6 a4 z
equivalent input noise at v2 = 19.4657n /rt hz
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**** the results of the sqrt of integral (v**2 / freq)
% F' a9 s. Z1 X, F, {5 D from fstart upto 1.0000x hz. using more freq points
& i# x+ n4 r' m! L2 Z! l results in more accurate total noise values.
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**** total output noise voltage = 2.3566m volts1 i" T0 r* I }) d7 A
**** total equivalent input noise = 19.1806u , f" ~+ F5 v$ ^$ }9 w: g$ M
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以上各种数据都表示什么含义啊?0 e4 }+ N6 ~4 x2 w
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?
1 V g% E: o# t$ s8 c, m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?$ ?( }) n- E" v0 Q5 J2 H
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