使用暫態分析模擬出phasenoise @ MMSIM701

gyamwoo

原文連結
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以下原文內容：

# ~: b9 c1 L+ r$ R, K- u" N7 bCalculating Large Signal Phase Noise Using Transient Noise Analysis
By Alan Whittaker on March 26, 2009
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) a! d0 f4 P+ W" CMy 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
" c* x( z$ ^: H$ Rduring 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
resolve issues that users have run into during the front-end analog, RF and
6 {1 v; @7 f0 B0 Amixed-signal design process.
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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
" h: t3 O0 G4 a4 P3 ucapability in our Spectre circuit simulator.  This approach is in addition to
our small signal phase noise analysis which is available using either pnoise
or hbnoise analysis in the SpectreRF option to Spectre.
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+ V- I+ K3 F( B/ R5 sHere 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
9 ~$ a/ u( E8 `7 N(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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2.  Add the block freq_meter from the pllMMLib library
($CDSHOME/tools//dfII/samples/artist/pllMMLib)
to the testbench circuit. Important: The instance name for this block must be
'vco_freq'.

If the oscillator output is differential, connect it to the vin_p and vin_n
6 s" V2 r& F# z. L% M  V* v6 u+ Vpins on the freq_meter block. If the oscillator output is single ended, connect
! Q: O: d; W: P. Z/ S9 Eit 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
+ }. u$ b, |4 K3 z1 o7 B' qparameter form:
    *
      Vthup: Threshold voltage to determine the rise edge of the input waveform.
The input waveform period is determined by two adjacent rise edges. Default is 0.
    *
      ttol: The tolerance of the time where the rise edge is determined. Default
is 1p.
    *
" }1 m2 |5 e3 T9 H2 {! a) b9 @      outStart: The time-dependent period of the input waveform is output to the
; z, C* M% T2 wfile when the time is greater than outStart. Default is 0. To get accurate phase
noise measurements, set this to past the time when the oscillator is fully
# a8 i% E: _7 W2 `# \& G5 cpowered up and oscillating at the design frequency.
    *
& s; u6 v$ P, ?2 X      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
8 K3 D9 w) T! {+ @* [- r3 s# x1 ^: Z3 Eleft 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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4.  Run the simulation. The simulation must run successfully to completion in order to get to the phase noise results.
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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.

: m' U3 m( j5 r  z$ aThe 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.

# `: `5 N; y+ m$ }% d& K. G5 O, zImportant 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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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
!!!
& X* Q1 _) p2 |# F; n, \!!!!!!!!!!!
/ S& B5 G3 S, i0 J6 }!!!!!!

gyamwoo

謝謝你的回覆，我最近拿到新的軟體也開始在測試mmsim7了
我發現turbo與multi thread的設定不同會對結果造成很大的不同。
3 I! M; i, y" N2 D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。
8 b. @/ n1 V; H, R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？