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原文連結
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2 b. o ~: n% j: _- {* E# u: F以下原文內容:- _: L o S. M; d3 p" G, e6 p
" d1 w( M7 d: R+ v+ T! _Calculating Large Signal Phase Noise Using Transient Noise Analysis
3 X0 n, ?5 [# G8 dBy Alan Whittaker on March 26, 2009
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: O3 c3 D9 F5 cMy name is Alan Whittaker and I'm in Cadence's Custom IC Proliferation Group. 2 l. {7 x( g7 N1 T9 V0 z$ q" M
We support Cadence's Technical Field Organization (the AEs) and Cadence customers / z8 s% S3 Q6 f
during the introduction and adoption of new and advanced EDA technologies. I'll
. S4 O3 d" N9 v% V; z5 r0 M7 i% mbe posting here from time to time on methodologies and tool features that
) d$ ]' r5 M4 a% q! @resolve issues that users have run into during the front-end analog, RF and
! \; I. Q* m2 U$ h% X/ D. omixed-signal design process.( P1 S# I- }9 V! C9 o- J
! B& Z: e$ T$ Y3 H1 O9 RI'm first going to address how you can perform a large-signal phase noise ! C. W4 e2 h6 a3 [+ @ W
analysis on a design block such as a VCO using our transient noise analysis " O2 m- x8 z) ]
capability in our Spectre circuit simulator. This approach is in addition to
- I8 @% ?. P% C7 i4 g# oour small signal phase noise analysis which is available using either pnoise , Q- h/ l: b0 t1 z) x: E6 u
or hbnoise analysis in the SpectreRF option to Spectre.
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9 r& r7 s4 s. y0 iHere are the steps to obtain a phase noise plot from transient noise analysis:& `3 R% `) U8 z0 G) t
0 u6 ^/ S8 H7 o9 r U8 n3 \3 G1. Set up your oscillator testbench circuit for a transient noise analysis
1 T/ n) B% _* O$ N7 `(See sourcelink for the Transient Noise appNote - it doesn't discuss the phase
$ b6 T3 c% ~5 [3 y% v. onoise measurement, but describes how to properly set up the simulation analysis
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2. Add the block freq_meter from the pllMMLib library
% t' }' L W$ [9 r4 L/ k2 z($CDSHOME/tools//dfII/samples/artist/pllMMLib) " s( C# [4 l4 P% b
to the testbench circuit. Important: The instance name for this block must be 2 O! W' H4 {! V }/ t$ I; O5 ^* e
'vco_freq'.
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If the oscillator output is differential, connect it to the vin_p and vin_n
( l; j4 [3 d s; _pins on the freq_meter block. If the oscillator output is single ended, connect \' I" Z# D4 U# [, F! M- j: j
it to the vin_p pin and connect the vin_n pin to ground. Connect a noConn cell
- p0 B- F% _; {, C) a5 sfrom the basic library to the out_freq pin. |
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