It is simply, the capability to amplify the input signal at its output after performing any due logic. to deliver high output current to a load. The “fan-out” is the ability of a Digital Buffer or Digital I.C.

This means that Digital Buffers have the “fan-out” capability to deliver high power to the output loads. Moreover, it can be used to drive high current loads such as switches or relays, etc. The Digital Buffer is useful in the isolation or separation of two circuits whereas the impedance of the input circuit does not affect the impedance of the output circuit. The Digital Buffer is used in digital circuits even though it does not perform any logic or decision. Figure 2: Digital Buffer constructed using logic “NOT” gates The process of “double inversion” leads to the formation of a Digital Buffer. First, the “NOT” gate inverts the input signal, and second, “NOT” inverts the inverted signal back to the original input signal. The connection of two logic “NOT” gates back-to-back in series form a Digital Buffer. The digital buffer can be constructed using a basic logic “NOT” gate. The symbol and truth table of a digital buffer is shown below: Figure 1: Digital Buffer symbol Its Boolean expression is given below: Q = Aįrom the expression, it is eminent that the output (Q) state of a digital buffer is only true when the input (A) is true otherwise the output (Q) is false.

The digital buffer is a non-inversion logic and follows Idempotent Law.

The input signal is reflected at the output of a digital buffer without any change in its logic. On the other hand, the digital buffer does not complement the input signal at its output. Likewise, when the input of a “NOT” gate is “LOW” then its output will NOT be “LOW”. As discussed in the logic “NOT” gate article, when the input of a “NOT” gate is “HIGH” then its output will NOT be “HIGH”. However, the logic “NOT” gate complements the input signal at its output. The digital buffer is similar to the logic “NOT” gate in a way that it is a two-terminal device having input and output terminals only.

The digital device used for such purposes is called Digital Buffer. Besides current amplification, the digital buffers provide isolation between input and output circuits where output is connected to some high-power load such as a relay, lamp or solenoid, etc. The digital buffers are used in digital circuits for the amplification of digital signals in order to drive high current loads.

Logicworks 5 tri state buffer