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原文連結% O8 S9 X; s3 W; x/ y* [9 o
, [5 N/ Y# |, h4 k3 l以下原文內容:
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$ @/ j1 ?5 o7 X, F, z* f8 JCalculating Large Signal Phase Noise Using Transient Noise Analysis @1 \0 C: p4 H. q6 d8 Q
By Alan Whittaker on March 26, 2009
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: Z& g4 ~7 f2 ?: H9 T+ jMy name is Alan Whittaker and I'm in Cadence's Custom IC Proliferation Group.
; A! w! C7 {- |" y8 f* ZWe support Cadence's Technical Field Organization (the AEs) and Cadence customers I& I9 z) x3 i5 B: ?- k
during the introduction and adoption of new and advanced EDA technologies. I'll : [. L1 R% c9 q @
be posting here from time to time on methodologies and tool features that
) @; |/ V7 k- {5 }resolve issues that users have run into during the front-end analog, RF and : M* f! ?) ?6 N& K7 {
mixed-signal design process.
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1 H$ e. o% k/ }6 d! E( YI'm first going to address how you can perform a large-signal phase noise $ n, p; l0 Z ?9 n F
analysis on a design block such as a VCO using our transient noise analysis 6 E' Z+ ^; l# z1 E3 g( [- B* W* |
capability in our Spectre circuit simulator. This approach is in addition to
: Y3 C9 t$ \8 U1 C% A) `2 E. Lour small signal phase noise analysis which is available using either pnoise - l; W2 H# G* r3 H; ?; @9 {* o
or hbnoise analysis in the SpectreRF option to Spectre.
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/ d N8 K$ T1 y9 QHere are the steps to obtain a phase noise plot from transient noise analysis:
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: ^, b S( R; c/ R$ k; [* ^& g2 N3 j1. Set up your oscillator testbench circuit for a transient noise analysis
$ m/ h& T. i. L: r) D6 H" V(See sourcelink for the Transient Noise appNote - it doesn't discuss the phase
- M# m" ^2 u$ ?7 tnoise 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
( b( x2 C! ` T6 D k* W- W($CDSHOME/tools//dfII/samples/artist/pllMMLib)
" K5 l- m5 l. X6 O3 ato the testbench circuit. Important: The instance name for this block must be
+ w3 j. N. s$ e l2 l4 t3 N' {'vco_freq'.0 F3 D! L7 U" ?+ P. e
. Y( k, `2 Q4 w4 w/ UIf the oscillator output is differential, connect it to the vin_p and vin_n
. |7 b/ n* D/ y7 e, |% r# ]pins on the freq_meter block. If the oscillator output is single ended, connect ( B5 Y7 W' r5 \9 M7 ]$ r+ T# ~
it to the vin_p pin and connect the vin_n pin to ground. Connect a noConn cell 1 ?9 Q# p6 N2 w
from the basic library to the out_freq pin. |
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