Encoder (digital)

An encoder (or "simple encoder") in digital electronics is a one-hot to binary converter. That is, if there are 2ⁿ input lines, and at most only one of them will ever be high, the binary code of this 'hot' line is produced on the n-bit output lines. A binary encoder is the dual of a binary decoder.

If the input circuit can guarantee at most a single-active input, a simple encoder is a better choice than a priority encoder, since it requires less logic to implement. However, a simple encoder can generate an incorrect output when more than a single input is active, so a priority encoder is required in such cases.