BIRD34.1 SPICE PROGRAM

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
Received on Thu May 2 17:13:06 1996