IMPEDANCE CALIBRATION CIRCUIT AND SEMICONDUCTOR DEVICE INCLUDING THE SAME

摘要

An impedance calibration circuit and a semiconductor device including the same are provided. An embodiment of the invention provides an impedance calibration circuit with a variable reference voltage generation unit. The impedance calibration circuit maximizes the number of semiconductor devices that can be tested in test equipment at one time and permits the operation of an impedance matching unit (e.g., an on-die-termination (ODT) circuit and/or an off-chip-driver (OCD)) to be tested for a variety of reference resistor values.