Encoder

The encoder is a logic  circuit  which  provides  the binary code is  output  for each input each input signal. In  other words  we can  say that it performs  just  opposite function  of a decoder. Th eblock  diagram  logic  diagram and truth  table of an 8 to 3  encoder ( 74LSI 148)  is shown in the fig.

Figure 8 to 3  Encoder

The output  lines Gs an E0  can be used for cascading  devices to encode more than  eight  inputs.

                                                                      Figure 8 to 3  Encoder