LTspice 模型參數

如何導入LTspice 模型 參數  keyword : LTspice 模型 Spice model  parameters

          這是1500MHZ_osc LTspice 電路圖

問題說明:
1) Fairchild  2N3904 Spice model 是:
 NPN (Is=6.734f Xti=3 Eg=1.11 Vaf=74.03 Bf=416.4 Ne=1.259 Ise=6.734  Ikf=66.78m Xtb=1.5 Br=.7371 Nc=2 Isc=0 Ikr=0 Rc=1 Cjc=3.638p Mjc=.3085  Vjc=.75 Fc=.5 Cje=4.493p Mje=.2593 Vje=.75 Tr=239.5n Tf=301.2p Itf=.4  Vtf=4 Xtf=2 Rb=10)

 但 ltspice 中 Philips廠商 的2N3904 之Spice model  是:

 NPN(IS=1E-14 VAF=100 Bf=300 IKF=0.4 XTB=1.5 BR=4 CJC=4E-12 CJE=8E-12 RB=20 RC=0.1 RE=0.1 TR=250E-9 TF=350E-12 ITF=1 VTF=2 XTF=3 Vceo=40
 Icrating=200m mfg=Philips)
但 ltspice 中 NEC廠商 的高頻電晶體2SC3357 之Spice model  是:

NPN (IS=684.2e-18 BF=161.1 NF=1.0 VAF=51 IKF=574.6e-3 BR=10.71 NR=1.0 VAR=2.1 IKR=28.05e-3 ISE=1.0e-18 NE=1.193 ISC=6.211e-18 NC=1.1 RB=3.0 IRB=75.9e-5 RBM=1.0 RE=2.67 RC=3.5 CJE=1.847e-12 VJE=1.014 MJE=464.8e-3 CJC=1.086e-12 VJC=617.4e-3 MJC=353.8e-3 XCJC=0.1 CJS=0 VJS=0.75 MJS=0 FC=0.50 TF=23e-12 XTF=0.39 VTF=0.668 ITF=0.06 TR=0 PTF=20 EG=1.11 XTI=3.0 XTB=0 Vceo=12 Icrating=100m mfg=NEC)

一些參數在兩個model中並非都有, 甚至一些參數在兩個model中都有但值不同.

例如: 在Fairchild Is=6.734f (6.734E-15=0.6734E-14),    在 ltspice  Is=1E-14 ,其中

1)不了解其中差異為何?

2)如果從元件製造商得到模型, 如何導入LTSPICE模型?

 例如: 從 Fairchild  拿到元件 MPSA42 的 Spice model 如下

 NPN (Is=34.9f Xti=3 Eg=1.11 Vaf=100 Bf=2.65K Ne=1.708 Ise=16.32p
 Ikf=23.79m Xtb=1.5 Br=9.769 Nc=2 Isc=0 Ikr=0 Rc=7 Cjc=14.23p Mjc=.5489
 Vjc=.75 Fc=.5 Cje=49.62p Mje=.4136 Vje=.75 Tr=934.3p Tf=1.69n Itf=5
 Vtf=20 Xtf=150 Rb=10)

 如何將此 model 導入 ltspice ?

3)如何自建LTspice 模型? 

問題解釋:

Q1)不了解其中差異為何?

ANS:

1)For the same device, the numbers vary a bit from maker to maker.
   You'll usually get a bit more accurate results using the maker's models.
   LTspice seems to have a list of default numbers that will be inserted if
   your model does not supply that particular parameter.

   To make your new device part of the normal component selection list when you
   run LTspice you need to edit a particular LTspice model file.

Q2)如果從元件製造商得到模型, 如何導入LTSPICE模型?

ANS:

2)The MPSA42 model text needs adding to the file LTspice/LIB/CMP/
   "standard.bjt". This is the store for all the PNP NPN transistors. Open it
   using 'Notepad', select and 'copy' the model text (I usually do this from
   the manufacturers web site) and paste onto the bottom of the list. If more
   than one line add a "+" at each new line start.
   Then add " mfg=Fairchild" and " Ic rating =123ma" (say).
   Philips and Fairchild models seem to correspond well with the real devices.

  Run LTspice and your added model will turn up as a normal component.

  更詳細的部驟參考6)補充說明

Q3)如何自建LTspice 模型? 

ANS:

3)???(建構中)

4)補充 關於spicce  GP模型說明,及內部參數定義:

           GP模型是1970年由H．K．Gummel和H．C．Poon提出的。GP模型對EM2模型在以下幾方面作了改進：

1.直流特性：反映了集電結上電壓的變化引起有效基區寬度變化的基區寬度調製效應， 改善了輸出電導、電流增益和特徵頻率。反映了共射極電流放大倍數β隨電流和電壓的變化。

2.交流特性：考慮了正向渡越時間τF隨集電極電流IC的變化，解決了在大注入條件下由於基區展寬效應使特徵頻率fT和IC成反比的特性。

3.考慮了大注入效應，改善了高電平下的伏安特性。

4.考慮了模型參數和溫度的關係。

5.根據橫向和縱向雙極電晶體的不同，考慮了外延層電荷存儲引起的准飽和效應。

以下是GP模型參數定義及預設值(Spice Gummel–Poon model parameters)

 http://en.wikipedia.org/wiki/Gummel–Poon_model

名稱  模型                    參數                                                                                                   單位    預設值

IS   current           transport saturation current                                                                         A    1.00E-016

BF   current          ideal max forward beta                                                                                  -        100

NF   current          forward current emission coefficient                                                            -          1

VAF  current        forward Early voltage                                                                                   V        inf

IKF  current          corner for forward beta high current roll-off                                                A       inf

ISE  current           B-E leakage saturation current                                                                     A         0

NE   current          B-E leakage emission coefficient                                                                  -         1.5

BR   current          ideal max reverse beta                                                                                   -           1

NR   current          reverse current emission coefficient                                                             -           1

VAR  current        reverse Early voltage                                                                                   V          inf

IKR  current         corner for reverse beta high current roll-off                                                 A         inf

ISC  current           B-C leakage saturation current                                                                   A          0

NC   current          B-C leakage emission coefficient                                                                 -           2

RB   resistance      zero-bias base resistance                                                                          ohms       0

IRB  resistance     current where base resistance falls half-way to its minimum                       A        inf

RBM  resistance   minimum base resistance at high currents                                                 ohms     RB

RE   resistance      emitter resistance                                                                                       ohms       0

RC   resistance      collector resistance                                                                                    ohms       0

CJE  capacitance   B-E zero-bias depletion capacitance                                                             F          0

VJE  capacitance   B-E built-in potential                                                                                    V        0.75

MJE  capacitance   B-E junction exponential factor                                                                    -        0.33

TF   capacitance     ideal forward transit time                                                                             s           0

XTF  capacitance   coefficient for bias dependence of TF                                                          -           0

VTF  capacitance   voltage describing VBC dependence of TF                                                  V          inf

ITF  capacitance     high-current parameter for effect on TF                                                      A           0

PTF                       excess phase at freq=1.0/(TF*2PI) Hz                                                        deg          0

CJC  capacitance    B-C zero-bias depletion capacitance                                                             F           0

VJC  capacitance    B-C built-in potential                                                                                    V        0.75

MJC  capacitance   B-C junction exponential factor                                                                     -         0.33

XCJC capacitance  fraction of B-C depletion capacitance connected to internal base node         -            1

TR   capacitance     ideal reverse transit time                                                                                s            0

CJS  capacitance     zero-bias collector-substrate capacitance                                                       F           0

VJS  capacitance     substrate junction built-in potential                                                               V         0.75

MJS  capacitance   substrate junction exponential factor                                                               -            0

XTB                       forward and reverse beta temperature exponent                                              -            0

EG                          energy gap for temperature effect of IS                                                          eV         1.1

XTI                        temperature exponent for effect of IS                                                              -            3

KF                          flicker-noise coefficient                                                                                    -            0

AF                          flicker-noise exponent                                                                                      -            1

FC                          coefficient for forward-bias depletion capacitance formula                              -           0.5

TNOM                  parameter measurement temperature                                                             deg.C       27

其他更詳細的說明參考如下:

BJT : http://web.engr.oregonstate.edu/~moon/ece323/hspice98/files/chapter_14.pdf

diode : http://web.engr.oregonstate.edu/~moon/ece323/hspice98/files/chapter_13.pdf

Star-Hspice Manual (PDF) (~11MB) 
Cover Sheets (22 KB)
Table of Contents (48 KB)
Index (175 KB)

1. Introducing Star-Hspice (23 KB)
2. Getting Started (90 KB)
3. Specifying Simulation Input and Controls (246 KB)
4. Specifying Simulation Output (192 KB)
5. Using Sources and Stimuli (355 KB)
6. DC Initialization and Point Analysis (146 KB)
7. Performing Transient Analysis (141 KB)
8. Using the .DC Statement (45 KB)
9. AC Sweep and Signal Analysis (137 KB)
10. Analyzing Electrical Yields (438 KB)
11. Optimizing Performance (338 KB)
12. Using Passive Devices (226 KB)
13. Using Diodes (134 KB)
14. BJT Models (467 KB)
15. Introducing MOSFET (576 KB)
16. Selecting a MOSFET Model (1,555 KB)
17. Using the Bipolar Transistor Model -VBIC (39 KB)
18. Finding Device Libraries (55 KB)
19. Performing Cell Characterization (212 KB)
20. Signal Integrity (422 KB)
21. Using Transmission Lines (655 KB)
22. Performing Behavioral Modeling (723 KB)
23. Using Meta I/O (62 KB)
24. Performing Pole/Zero Analysis (138 KB)
25. Performing FFT Spectrum Analysis (221 KB)
26. Modeling Filters and Networks (513 KB)
27. Timing Analysis Using Bisection (105 KB)
28. Performing Library Encryption (30 KB)
29. Running Demos (191 KB)



 5)  other LINK:http://ecee.colorado.edu/~bart/book/book/chapter5/ch5_6.htm

    SPICE BJT Parameters  (spice BJT  參數定義)
    ----------------------------------
    BF      Forward active current gain
    BR      Reverse active current gain
    IS       Transport saturation current
   CJE    Base-emitter zero-bias junction capacitance
   CJC    Base-collector zero-bias Junction capacitance
   VJE   Base-emitter built-in potential
   VJC   Base-collector built-in potential
   VAF   Forward mode Early voltage
   VAR  Reverse mode Early voltage
   NF     Forward mode ideality factor
   NR    Reverse mode ideality factor