Joe G (Home) said:
Hi All,
Does anyone know where I might be able to obtain this model.
Thanks in advance.
Regards
Joe
Hello Joe,
The important question is what behaviour should be modeled.
If you want make a simple digital inverter, then an A-device with Vhigh,
Vlow, Ref, Trise and Td will fit. This A-device will be simulated very fast.
Vhigh=5 Ref=2.5 Td=5 Trise=5
I recommend to add a 50 Ohm resistor in series to the output. Adding
the built-in input diodes may be also necessary if the input voltage exceeds
the rails.
I have written a small library based on the A-models. It's in the
LTspice Yahoo group. The devices fom this library will run slower
than pure A-devices.
http://tech.groups.yahoo.com/group/LTspice/
NXP offers a real transistor level model. A simulation will run slower
than with a simple A-device of course too.
http://www.standardics.nxp.com/support/models/spice/zip/hc.zip
http://www.standardics.nxp.com/support/models/spice/
Best regards,
Helmut
Example schematic(circuit), file name "74hc04_a.asc"
Version 4
SHEET 1 880 680
WIRE -528 -16 -576 -16
WIRE -576 16 -576 -16
WIRE -48 64 -48 32
WIRE -576 128 -576 96
WIRE -464 176 -576 176
WIRE -48 176 -48 128
WIRE -48 176 -192 176
WIRE 64 176 -48 176
WIRE 160 176 128 176
WIRE 368 176 240 176
WIRE -576 208 -576 176
WIRE -48 240 -48 176
WIRE -576 336 -576 288
WIRE -48 336 -48 304
FLAG -48 32 VCC
FLAG -48 336 0
FLAG -576 336 0
FLAG 368 176 out
IOPIN 368 176 Out
FLAG -464 176 in
IOPIN -464 176 Out
FLAG -576 128 0
FLAG -528 -16 VCC
FLAG -192 176 in
IOPIN -192 176 In
SYMBOL Digital\\inv 64 112 R0
WINDOW 123 -17 130 Left 0
WINDOW 39 -12 162 Left 0
SYMATTR InstName A1
SYMATTR Value2 Vhigh=5 Ref=2.5
SYMATTR SpiceLine Trise=5n Td=5n
SYMBOL res 144 192 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R1
SYMATTR Value 50
SYMBOL diode -64 128 M180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D1
SYMATTR Value DD
SYMBOL diode -64 304 M180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D2
SYMATTR Value DD
SYMBOL voltage -576 192 R0
WINDOW 123 24 160 Left 0
WINDOW 39 24 132 Left 0
SYMATTR InstName V1
SYMATTR Value PULSE(0 5 10n 5n 5n 45n 100n)
SYMATTR Value2 AC 1
SYMATTR SpiceLine Rser=50
SYMBOL voltage -576 0 R0
SYMATTR InstName V2
SYMATTR Value 5
TEXT -96 392 Left 0 ;optional
TEXT 0 336 Left 0 !.model DD D(Cjo=5p Rs=10)
TEXT 64 -32 Left 0 ;74HC04
TEXT -584 -128 Left 0 !.tran 0 250n 0 .1n
TEXT -584 -96 Left 0 !.options plotwinsize=0
RECTANGLE Normal 320 432 -144 -64 2
CIRCLE Normal 16 368 -112 -32 2