|
原文連結% V8 N4 V+ e: Y0 ^
+ v( H1 a3 W$ l1 ~# Q7 P7 b以下原文內容:+ }0 \4 Y, S) t/ P" A9 W; V* W
$ j: Q6 V( w$ ?2 fCalculating Large Signal Phase Noise Using Transient Noise Analysis
5 J5 x* j$ p, Q+ sBy Alan Whittaker on March 26, 2009- i9 R% Q( o P- S% Z
/ n* }9 O( Q. y; bMy name is Alan Whittaker and I'm in Cadence's Custom IC Proliferation Group. ) ~, F. W# W1 v0 O4 C9 w! o
We support Cadence's Technical Field Organization (the AEs) and Cadence customers
0 y' t2 o/ Q& u0 ~0 `" V* n7 pduring the introduction and adoption of new and advanced EDA technologies. I'll
( S* R- B0 v+ M" P5 E# a( u% _+ C6 Zbe posting here from time to time on methodologies and tool features that
1 Y: j( s7 T7 k7 h4 vresolve issues that users have run into during the front-end analog, RF and
0 ^- Q' i% ]7 s9 {9 I* e6 dmixed-signal design process.
0 U8 @4 ?. C) @' u; m
5 o( N% q$ U. p# B5 K- J9 JI'm first going to address how you can perform a large-signal phase noise ! x6 g8 A8 \) Y1 M+ i
analysis on a design block such as a VCO using our transient noise analysis , Z! o4 Z% ]/ L b- W
capability in our Spectre circuit simulator. This approach is in addition to
7 d$ p3 \( Y4 g" zour small signal phase noise analysis which is available using either pnoise ; B) W2 |/ ]) M8 y0 M
or hbnoise analysis in the SpectreRF option to Spectre." U& J7 B/ d {1 _
4 U2 |8 H( b3 m7 L& ?4 s
Here are the steps to obtain a phase noise plot from transient noise analysis:' N9 f$ p6 N' G4 |# ^
- m$ \, Q: H9 |5 F7 x/ H. b9 A$ F
1. Set up your oscillator testbench circuit for a transient noise analysis
& R4 X3 Q. @# L6 V(See sourcelink for the Transient Noise appNote - it doesn't discuss the phase N9 {9 ~2 e8 s- z; @
noise measurement, but describes how to properly set up the simulation analysis7 N9 j3 L' C) o$ @/ D
% w/ z) \# _ H7 b3 B$ t y
2. Add the block freq_meter from the pllMMLib library 1 j, N( [/ W5 s' @% k" A& ^
($CDSHOME/tools//dfII/samples/artist/pllMMLib)
5 O# ^1 u$ K# G; d. l+ A; q7 sto the testbench circuit. Important: The instance name for this block must be
' j" f5 B9 b' n0 v2 b0 t'vco_freq'.
5 _7 ~: d8 e6 m6 N0 ]0 {7 j
9 t0 S8 V3 ^6 c% `4 O5 zIf the oscillator output is differential, connect it to the vin_p and vin_n
& s9 }% N( U2 R+ Z% Z0 Bpins on the freq_meter block. If the oscillator output is single ended, connect
1 P! H0 m; ^8 K0 i2 r5 |9 wit to the vin_p pin and connect the vin_n pin to ground. Connect a noConn cell
$ p. N. ]5 b h; }3 s. {" X9 m* afrom the basic library to the out_freq pin. |
|