Simple D flip flop Spice Model

[guitargore]

Does anyone have a simple spice model for a D flip flop? Our simulator doesn't have any special spice libraries to work with so we need a primitive model. Just looking for basic functionality, don't really care about slew, drive strength, metastability, or any of that.

 

[atripathi]

Which simulator you are using? if you are using PSpice, you shall be able to get the one from installed libraries. CD4013B is one such device from CD4000 library.
You may not find a generic SPICE model for D flipflop as original SPICE does not have support for digital simulation.

 

[guitargore]

We're using Altium Designer here, so all we have is the standard spice. We don't really care how generic or specific the model is, we just want something so we can confirm basic circuit functionality.

 

[guitargore]

My coworker was able to work something up for a d flip flop:

*SRC=74HC74
*SYM=74HC74
.SUBCKT 74HC74 1 2 3 4 5 6 7 14
*1=CLR 2=D 3=CLK 4=SET 5=Q 6=Q\ 7=GND 14=VCC
* 20=Momentary Clock 21=Q before RC 22=Q after RC 23=VCC that we can look
R1 14 23 1
R2 14 20 1
R3 21 22 1
C1 3 20 0.0000001 IC=0
C2 22 7 0.0000001 IC=0
B1 21 7 V = IF( (((V(1,7))<((V(23,7))/2)) + (((V(20,7))<((V(23,7))/2)) * ((V(2,7))<((V(23,7))/2)))), 0, (IF((((V(4,7))<((V(23,7))/2)) + (((V(20,7))<((V(23,7))/2)) * ((V(2,7))>((V(23,7))/2)))), V(23,7), V(5,7))) )
B2 5 7 V = IF((V(22,7)<(V(23,7))/2),0,(V(23,7)))
B3 6 7 V = IF((V(5,7)>(V(23,7))/2),0,(V(23,7)))
.ENDS

Any comments would be appreciated, this has been tested and confirmed to work on our simulator. Also the 74HC74 is just to remind my coworker what it is because he is good with chip numbers, i am not.

 

[dick_freebird]

The Yahoo! LTSpice group maintains a very large archive
of subcircuit models. You should be able to find one that
doesn't use nonstandard elements.