Patent ID: 8519738
Filing Date: 2013-08-27
Classification: H03H

Abstract:
1. A semiconductor apparatus comprising: a first calibration unit configured to compare a first converted voltage obtained by converting a first calibration signal with a reference voltage and vary the first calibration signal; a second calibration unit, operatively coupled to the first calibration unit, configured to compare a second converted voltage obtained by converting a second calibration signal with the level of the first converted voltage and vary the second calibration signal; an impedance matching circuit, operatively coupled to the first calibration unit and to the second calibration unit, configured to set impedance of signal input/output terminals to a target value according to the first and second calibration signals; a state machine configured to generate a variety of commands for deciding an impedance calibration time; and a timer counter, operatively coupled to the state machine, the first calibration unit and the second calibration unit, and configured to generate a variety of control signals for controlling the first and second calibration units.