Definition of fanout in TTL logic In TTL logic families, the specification “ten TTL loads per TTL driver” refers to which parameter?

Introduction / Context:Fanout defines how many standard logic inputs a single gate output can drive while still meeting valid logic level specifications. It is crucial in digital system loading and buffering decisions.

Given Data / Assumptions:

• Standard TTL logic levels and input currents.
• “Ten TTL loads” implies a normalized loading standard.
• Proper power and ground practices.

Concept / Approach:Fanout is the ratio of the maximum source/sink current capability of an output to the input current required by a standard load. In classic TTL, an output characterized to drive ten standard inputs has a fanout of 10. Staying within fanout preserves VOH/VOL margins and timing integrity.

Step-by-Step Solution:Identify parameter: number of inputs driven per output.Interpret “ten loads”: equals fanout of 10.Conclude mapping: the given statement is the fanout specification.

Verification / Alternative check:Datasheets specify I_OH/I_OL and I_IH/I_IL; fanout_low ≈ I_OL / I_IL and fanout_high ≈ I_OH / I_IH. Typical older TTL values support fanout around ten.

Why Other Options Are Wrong:Noise immunity: relates to voltage margins, not loading count.Power dissipation: describes energy use, not drive capability.Propagation delay: timing parameter, not loading quantity.

Common Pitfalls:Ignoring capacitive loading and trace fanout which affect edges and timing even within dc fanout limits. Consider buffering for high-speed nets.

Final Answer:fanout