The IC Card Interface IP provides power supply for either 1.8V, 3V, or 5V Smart/SAM cards, and realizes level-shift between smart card controller and smart card, using SMIC 0.18um Mixed-Signal CMOS process. This IP mainly consists of two parts, the Power MUX and IC Card I/O. The Power MUX provides one of 1.8V, 3V, or 5V voltage to smart card under the control of smart card. The IC Card I/O can shift the Smart Card interface voltages of both controller side and card side no matter the power of which side is higher.