Digital Buffer:

A buffer may be realized by using a switch as depicted in Figure (a), which is operated by the input voltage V_i. Whereas V_i is low, the switch is connected to ground and output voltage V₀ is low. Whereas V_i is high, the switch is connected to V_cc and the output voltage V₀ is high. It may be tabulated in the form of a truth table as illustrated in Figure (b), where the output follows the value of the input. Figure (c) illustrates the symbol of a Digital Buffer.

(a)                                  (b)                     (c)

Figure: (a) Switch Configuration, (b) Truth Table, and (c) Symbol of a Digital Buffer