Subject: BIRD34.1 SPICE PROGRAM

From: [email-masked] ( Bob Ross)
Date: Thu, 2 May 96 17:05 PDT

To IBIS Committee:

Below is an HSPICE program which demonstrates the transit time stored
charge effect that BIRD34.1 is addressing.  You can vary the Rdiode 
and TTdiode parameters.

Bob Ross
Interconnectix, Inc.

* STORED CHARGE DEMONSTRATION PROGRAM 1
*
* 5 V 10 ohm 1 nS Source, Z0 = 50, Td = 1 n Line:
*
*                                           DUT with [Gnd Clamp]
*                           ____________       | /|
*              o---/\/\/\--O____________)---o--|< |--o GND
*                 10 ohms    Z0 = 1 nS      |  | \|  |
*                            TD = 50 ohms   |        |
*                                           |-/\/\/\-|
*                                           | 500 ohm Load for Probing
*    Vcc ---\                 ------\       |
*            \                       \      o      /--\
*    0 V      \------                 \           /    \-------
*           | |                        \---------/
*           1 nS                   |<----------->|
*       1 nS, 10 ohm             Choose TTgnd that matches the measured 
*       Source Signal            delay with the IBIS model simulation delay
*                                  
*                     Example of TTgnd Extraction Setup
*
*
*			  
*		   Intrinsic
*	     RS      Diode                        +-----+
*		      |\ | ----> Id               |     | ----> Id
*      o---/\/\/\--+--| >|--+----o          +-----|Clamp|-----+
*		   |  |/ |  |               |     |     |     |
*		   |        |          o----|     +-----+     |----o
*		   |   | |  |               |       | |       |
*		   +---| |--+               +-------| |-------+
*		       | |                          | |
*
*		     Cj + Ct                     C_comp + Ct
*
*
*                    Spice Model Vs IBIS Model Structure
*
*
*
*    IBIS Ct EQUATION:
*
*       Ct = TT * (q/KT) * Id
*          = TT * (38.4) * Id 
*            at T = 27 deg C (300 deg K)
*
*       Note, Cj and C_comp = 0 in this example
*
*    REFERENCE OUTPUTS
*
*       V(11)  Unterminated line 
*                                   RS       TT
*       V(21)  Default Diode        0        0
*       V(31)  Default Diode        0        TTdiode
*       V(41)  Default Diode        Rdiode   0
*       V(51)  Default Diode        Rdiode   TTdiode
*
*    IBIS EQUIVALENT OUTPUTS
*                                                   RS_Ext    TT     Equivalence
*       V(61)  Default Diode        0         0     Rdiode    Ct     V(51)
*              (TT across Diode Only)
*       V(71)  Default Diode        0         0     Rdiode    Ct
*              (TT across Diode and RS_ext)
*       V(81)  Table Diode          0         0     Rdiode    Ct     V(71)
*              (TT across Table Diode and RS_ext)
*       V(91)  Table RS Diode       0         0     0         Ct     V(71) with
*              (TT across Table Diode including RS=10                  RS=10
*
*    DIODE PARAMETERS
*

.PARAM  Rdiode = 10
.PARAM  TTdiode = 10n

*    INPUT PULSE

VIN 1 0 PULSE (5 0 0 1n 1n 15n 100n)

****** REFERENCE SIMULATIONS ***********

* NO TERMINATION
RS1  1  10   10
T1   10 0 11 0 Z0=50 TD=1n
RL1  11 0    500

* DEFAULT DIODE
RS2  1  20   10
T2   20 0 21 0 Z0=50 TD=1n
RL2  21 0    500
D2   0  21   D1

* DEFAULT DIODE, TT=TTdiode
RS3  1  30   10
T3   30 0 31 0 Z0=50 TD=1n
RL3  21 0    500
D3   0  31   D2

* DEFAULT DIODE, RS=Rdiode
RS4  1  40   10
T4   40 0 41 0 Z0=50 TD=1n
RL4  41 0    500
D4   0  41   D3

* DEFAULT DIODE, TT=TTdiode, RS=Rdiode
RS5  1  50  10
T5   50 0 51 0 Z0=50 TD=1n
RL5  51 0    500
D5   0  51   D4

******* IBIS EQUIVALENT SIMULATIONS *********

* DEFAULT DIODE, RS=0, TT=0,  Ct Equation, External RS=RSdiode
* Ct ACROSS DIODE ONLY
RS6  1  60   10
T6   60 0 61 0 Z0=50 TD=1n
R6   61 62   Rdiode
V6   63 62   0
D6   0  63   D1
RL6  61 0    500
C6   62 0    C='(TTdiode*I(V6)*38.4+1e-15)'

* DEFAULT DIODE, RS=0, TT=0,  Ct Equation, External RS=RSdiode
* Ct ACROSS TOTAL STRUCTURE
RS7  1  70   10
T7   70 0 71 0 Z0=50 TD=1n
R7   71 72   Rdiode
V7   73 72   0
D7   0  73   D1
RL7  71 0    500
C7   71 0    C='(TTdiode*I(V7)*38.4+1e-15)'

* DEFAULT DIODE, RS=0, TT=0,  Ct Equation, External RS=RSdiode
* Ct ACROSS TOTAL STRUCTURE
RS8  1  80   10
T8   80 0 81 0 Z0=50 TD=1n
R8   81 82   Rdiode
V8   83 82   0
XD8  0  83   D1TABLE
RL8  81 0    500
C8   81 0    C='(TTdiode*I(V8)*38.4+1e-15)'

* DEFAULT DIODE, RS=0, TT=0,  Ct Equation, External RS=0
* TABLE BASED ON 10 OHMS IN SERIES
* Ct ACROSS TOTAL STRUCTURE
RS9  1  90   10
T9   90 0 91 0 Z0=50 TD=1n
V9   93 91   0
XD9  0  93   D3TABLE
RL9  91 0    500
C9   91 0    C='(TTdiode*I(V9)*38.4+1e-15)'

.MODEL D1 D( TT=0n RS=0 )
.MODEL D2 D( TT=TTdiode RS=0 )
.MODEL D3 D( TT=0n RS=Rdiode )
.MODEL D4 D( TT=TTdiode RS=Rdiode )

* D1 DIODE TABLE
.SUBCKT  D1TABLE  2  1
G1   1   2   PWL(1)  1  2
+  -5.00000    -1.288e+17  
+  -1.50000    -226.9724g  
+  -1.40000      -4.6299g  
+  -1.30000     -94.4445e6  
+  -1.20000      -1.9265e6  
+  -1.10000     -39.2989k  
+  -1.00000    -801.6450   
+ -900.00000m    -16.3525   
+ -800.00000m   -333.5690m  
+ -700.00000m     -6.8044m  
+ -600.00000m   -138.7999u  
+ -500.00000m     -2.8313u  
+ -400.00000m    -57.7558n  
+ -300.00000m     -1.1784n  
+ -200.00000m    -24.2224p  
+ -100.00000m   -580.2281f  
+   0.            0.       
+   5             0.
.ENDS

* D3 DIODE TABLE WITH FIXED 10 Ohm Series R
.SUBCKT  D3TABLE  2   1
G3   1   2   PWL(1)   1  2
+  -5.00000    -419.4116m  
+  -4.90000    -409.4733m  
+  -4.80000    -399.5364m  
+  -4.70000    -389.6011m  
+  -4.60000    -379.6674m  
+  -4.50000    -369.7355m  
+  -4.40000    -359.8055m  
+  -4.30000    -349.8774m  
+  -4.20000    -339.9513m  
+  -4.10000    -330.0274m  
+  -4.00000    -320.1058m  
+  -3.90000    -310.1867m  
+  -3.80000    -300.2702m  
+  -3.70000    -290.3564m  
+  -3.60000    -280.4457m  
+  -3.50000    -270.5381m  
+  -3.40000    -260.6339m  
+  -3.30000    -250.7334m  
+  -3.20000    -240.8369m  
+  -3.10000    -230.9446m  
+  -3.00000    -221.0570m  
+  -2.90000    -211.1745m  
+  -2.80000    -201.2976m  
+  -2.70000    -191.4268m  
+  -2.60000    -181.5627m  
+  -2.50000    -171.7061m  
+  -2.40000    -161.8579m  
+  -2.30000    -152.0190m  
+  -2.20000    -142.1907m  
+  -2.10000    -132.3745m  
+  -2.00000    -122.5721m  
+  -1.90000    -112.7859m  
+  -1.80000    -103.0186m  
+  -1.70000     -93.2739m  
+  -1.60000     -83.5565m  
+  -1.50000     -73.8730m  
+  -1.40000     -64.2322m  
+  -1.30000     -54.6473m  
+  -1.20000     -45.1383m  
+  -1.10000     -35.7386m  
+  -1.00000     -26.5064m
+ -900.00000m    -17.5637m  
+ -800.00000m     -9.2196m  
+ -700.00000m     -2.5359m  
+ -600.00000m   -131.8561u  
+ -500.00000m     -2.8282u  
+ -400.00000m    -57.7545n  
+ -300.00000m     -1.1784n  
+ -200.00000m    -24.2224p  
+ -100.00000m   -580.2281f  
+   0.            0.     
+   5             0.  
.ENDS

.TRAN 10P 15N 
.OPTIONS POST METHOD=GEAR
.END