An output that drives several logic inputs must supply the sum of their input currents, so fanout starts as an addition ledger. The 1 A input loads and 5 A output limit here are exact training values, not real logic-family specifications; actual interface budgets use datasheet currents, voltage margins, temperature ranges, and measurement uncertainty.
A logic output can drive several inputs only if the exact input currents fit the output limit. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Input currents add
Each input load draws 1 ampere in this training model. With 4 loads, the total is 4 amperes.
Itotal=4⋅1A=4A
The total is below the output limit
The output limit is 5 amperes, so this fanout passes. These are exact training currents, not real logic-family specifications.