A peripheral component interconnect express (PCIe) interface device is provided to include: a root complex configured to support a PCIe port, a memory connected to an input/output structure through the root complex, a switch connected to the root complex through a link and configured to transmit a transaction, and an end point connected to the switch through the link to transmit and receive a packet. The PCIe interface device may perform a link power management by changing a state of the link in response to a detection of an idle state of the link.