Patent ID: 9553587
Date: 2017-01-24
CPC Classifications: H03K

Claim:
1. A data output circuit of a semiconductor apparatus, comprising: a pull-up driver including a plurality of leg units which are configured to pull up a data output pad in response to data, and configured in such a manner that, in the case where a termination resistance value of an external system is a first preset value, one leg unit among the plurality of leg units is activated according to selection signals when an output voltage of the data output pad is set to a first output voltage and two leg units among the plurality of leg units are activated according to the selection signals when the output voltage is set to a second output voltage; a pull-down driver configured to pull down the data output pad in response to the data; a control block configured to generate the selection signals in response to mode register signals; and a code generator configured to control resistance values of the plurality of respective leg units to predetermined resistance values based on an external resistor.