使用暫態分析模擬出phasenoise @ MMSIM701

gyamwoo

原文連結

以下原文內容：

Calculating Large Signal Phase Noise Using Transient Noise Analysis
By Alan Whittaker on March 26, 2009

My name is Alan Whittaker and I'm in Cadence's Custom IC Proliferation Group.  
We support Cadence's Technical Field Organization (the AEs) and Cadence customers
during the introduction and adoption of new and advanced EDA technologies.  I'll
be posting here from time to time on methodologies and tool features that
0 @6 i1 u1 d$ ^" Yresolve issues that users have run into during the front-end analog, RF and
mixed-signal design process.

9 {- r; c  l. {I'm first going to address how you can perform a large-signal phase noise
analysis on a design block such as a VCO using our transient noise analysis
8 Q+ O: ^0 G6 c5 ~capability in our Spectre circuit simulator.  This approach is in addition to
+ |1 h2 {! X" b8 Iour small signal phase noise analysis which is available using either pnoise
or hbnoise analysis in the SpectreRF option to Spectre.
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Here are the steps to obtain a phase noise plot from transient noise analysis:

1.  Set up your oscillator testbench circuit for a transient noise analysis
(See sourcelink for the Transient Noise appNote - it doesn't discuss the phase
noise measurement, but describes how to properly set up the simulation analysis
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% H9 Z$ f+ i) m+ S2.  Add the block freq_meter from the pllMMLib library
($CDSHOME/tools//dfII/samples/artist/pllMMLib)
3 m& J$ }1 m. w5 g, w8 tto the testbench circuit. Important: The instance name for this block must be
8 {$ [5 b8 H. B1 ]9 w'vco_freq'.
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If the oscillator output is differential, connect it to the vin_p and vin_n
4 t1 A1 ]  s( q# H# Q/ I) E: ]pins on the freq_meter block. If the oscillator output is single ended, connect
8 u% O9 ~9 A. b* Mit to the vin_p pin and connect the vin_n pin to ground. Connect a noConn cell
from the basic library to the out_freq pin.

gyamwoo

The parameters for this block are (set Tools Filter to veriloga in the CDF
) p" K) v1 f& ?  x( G8 eparameter form:
0 `" L$ M- a( D2 v" I5 v    *
0 z' F6 I$ m, ~- e! D) w' `      Vthup: Threshold voltage to determine the rise edge of the input waveform.
* x. |( r  D' ]The input waveform period is determined by two adjacent rise edges. Default is 0.
% M# B* M  [, q9 i    *
      ttol: The tolerance of the time where the rise edge is determined. Default
( [4 K! O- g- [, _6 L! Pis 1p.
    *
$ p( R& Y; r3 O/ o' {      outStart: The time-dependent period of the input waveform is output to the
8 T! O" K+ k- [1 t7 o/ K6 s$ s" X  qfile when the time is greater than outStart. Default is 0. To get accurate phase
' q" V  V4 f6 {" s) z6 V4 Cnoise measurements, set this to past the time when the oscillator is fully
powered up and oscillating at the design frequency.
" u; G* e. w3 _7 s2 |8 K    *
      outfile: The name of a file to contain time-dependent periods for use in
later psd calculations. Specify just the file name, not a path. If outfile is
5 M& B$ h! T! c! C! O5 H( o/ Mleft blank, the default name is periods.txt.

gyamwoo

3.  Before starting the simulation, in the ADE window, Select Tools->RF->LL. In the PLL Macro Model Wizard window, enable PLL Macro Model and select PLL Bench as the Bench Type. Then OK this form.
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( i  ~& A; B; q; l7 O0 A' O4.  Run the simulation. The simulation must run successfully to completion in order to get to the phase noise results.

5.  In the Direct Plot form for transient noise there should be a PLL PSD Noise option. This will allow you to plot the phase noise results. If a message appears saying that the PLL Noise PSD data is not available, check steps 3) and 4). If you make any corrections, you will need to re-run the simulation.
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The phase noise plot will extend from fmin = 4/tstop to fmax = fosc/2, where tstop is the transient noise simulation stop time and fosc is the oscillation frequency of the circuit.
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Important note: You will need to use MMSIM701 and IC5141USR5 or IC613 (or latersubversions) to obtain a phase noise plot from transient noise analysis.
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' g  R! V1 P3 [, Q# s" _我用的是mmsim620，也不能模。有人可以模擬出來的回個文，show個圖給大家看吧

macrohan

show you my simulation result
9 b* V4 W' v' e' t& M! J: m!!!
!!!!!!!!!!!
. c. U+ W" Q% M5 x!!!!!!

gyamwoo

謝謝你的回覆，我最近拿到新的軟體也開始在測試mmsim7了
6 i2 D* [# p1 r, s! p/ ~( ~/ `2 L我發現turbo與multi thread的設定不同會對結果造成很大的不同。
還有這個phase noise的訊號的範圍跟transient noise的設定與transient 的設定都有很緊密的關係。
不知道該怎麼作設定才是比較準確的

kunhsun

請問有更詳盡的使用方法嗎

duoyun

也去试试这个流程。关于pll相噪仿真还有其他方法吗？