Hi Mahmood,
Registering with TI is not very difficult if you have a business or university email address.
You can then download the free version, PSPICE-FOR-TI, from the e-fuse product page.
But do you really need to simulate the e-fuse? In the past, we used a few different types of these without simulation or issues.
The only tricky thing is the fixed overvoltage protection of some TPS26636 variants (e.g. TPS26632), which prevents use at higher voltages.
You could ask specific questions on the TI E2E? forum. The people there are very friendly (as they are on this forum).
Sven.
