what is Fan-out

• the fan-out is the number of gate inputs driven by the output of another single logic gate.
• 扇出（fan-out）是一个定义单个逻辑门能够驱动的数字信号输入最大量的专业术语。
• 大多数的TTL逻辑门能够为10个其他数字门或驱动器提供信号。所以，一个典型的TTL逻辑门有10个扇出信号。
• In most designs, logic gates are connected to form more complex circuits. While no logic gate input can be fed by more than one output at a time without causing contention, it is common for one output to be connected to several inputs. The technology used to implement logic gates usually allows a certain number of gate inputs to be wired directly together without additional interfacing circuitry. The maximum fan-out of an output measures its load-driving capability: it is the greatest number of inputs of gates of the same type to which the output can be safely connected.
• 在大多数设计中，逻辑门被连接起来形成更复杂的电路。虽然没有逻辑门输入可以由多个输出同时提供而不引起争用，但一个输出连接到多个输入是常见的。用于实现逻辑门的技术通常允许一定数量的门输入直接连接在一起，而不需要额外的接口电路。输出的最大扇出测量其负载驱动能力:它是输出可以安全连接的同类型门的最大输入数量。