Fatal Error in Tanner Spice

[venkateshjuturu]

here i am attaching two images, one image shows code and the other shows fatal error

my problem is i want to print a exponential current pulse in tanner spice with Tr=50ps, Tf=164ps


please any one can help me in solving this problem

thanks in advance

 

[erikl]

I think you need to change

1. the node GND ; it is unknown. Change it to "0", or insert a Vsource with value zero between GND and 0
2. in the exp expression: the (second) fall delay from 0 to at least 3 or more rise times
3. ... and adapt the .tran expression to a reasonable simulation time resolution and range


So I'd suggest:

ifg node [U]0[/U] exp(0 10m 0 50p [U]500p[/U] 164p)
.tran [U]2p 2n[/U]