how can find the maximum fan-out of the TTL-NAND gate using LTSpice ? i tried to solve problem by hand, but the problem how to find fan-out using ltspice
It can be done. Make a simulated circuit using the NAND gate driving some TTL inverters. Keep adding inverters until the NAND gate's low level is no longer low enough to make the inverter outputs high. That's not the right way to find the fanout, though. You would only do so if you're sure you're not misreading an idiotic homework assignment. @Long Pham's comment is correct and all you need to know.