A data output circuit of a semiconductor apparatus includes a pull-up driver including a first plurality of leg units commonly electrically coupled to a data output pad and configured to pull up the data output pad in response to a first code signals, a pull-down driver including a second plurality of leg units commonly electrically coupled to the data output pad and configured to pull down the data output pad to a second code signals, and a code generator configured to generate the first and second code signals. The code generator generates the second code signals by comparing a replica voltage to a reference voltage.