Subject: BIRD34.1 2ND SPICE PROGRAM

From: [email-masked] ( Bob Ross)
Date: Thu, 2 May 96 17:11 PDT

To IBIS Committee:

This test program uses a different test setup.  With this setup, the
simlation output V(81) appears to be sensitive to the discrete diode
table representation.  It should be very close to V(71) and V(91) for
Rdiode = 10 ohms.

Bob Ross,
Interconnectix, Inc.

* STORED CHARGE DEMONSTRATION PROGRAM 2
*
* -2 V to Vcc 50 ohm 1 nS Source, 50 ohm Load:
*
*
*			       DUT with [Gnd Clamp]
*		    50 ohms       | /|
*   Pulse Source o---/\/\/\----o--|< |--o GND
*   -2 V to Vcc                |  | \|  |
*			       |        |
*			       |-/\/\/\-|
*			       | 50 ohm Probe Load
*			       
*		  Vcc/2       /----- /-------
*			     /      / 
*	    Without DUT ->  /      / <- With DUT      
*			___/------/ 
*		  -1 V              
*			  |       | Choose TTgnd such that measured delay
*				    equals IBIS model simulation delay 
*
*		       Example of TTgnd Extraction
*	
*			  
*		   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

.PARAM  VCC = 5

VIN 1 0 PULSE (-2 VCC 0 1n 1n 15n 100n)

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

* NO TERMINATION
RS1  1  11  50
RL1  11 0   50

* DEFAULT DIODE
RS2  1  21  50
RL2  21 0   50
D2   0  21  D1

* DEFAULT DIODE, TT=TTdiode
RS3  1  31  50
RL3  31 0   50
D3   0  31  D2

* DEFAULT DIODE, RS=Rdiode
RS4  1 41   50
RL4  41 0   50
D4   0  41  D3

* DEFAULT DIODE, TT=TTdiode, RS=Rdiode
RS5  1  51  50
RL5  51 0   50
D5   0  51  D4

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

* DEFAULT DIODE, RS=0, TT=0,  Ct Equation, External RS=RSdiode
* Ct ACROSS DIODE ONLY
RS6  1  61  50
R6   61 62  Rdiode
V6   63 62  0
D6   0  63  D1
RL6  61 0   50
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  71  50
R7   71 72  Rdiode
V7   73 72  0
D7   0  73  D1
RL7  71 0   50
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  81  50
R8   81 82  Rdiode
V8   83 82  0
XD8  0  83  D1TABLE
RL8  81 0   50
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  91  50
V9   93 91  0
XD9  0  93  D3TABLE
RL9  91 0   50
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 5N 
.OPTIONS POST METHOD=GEAR
.END