This document discusses, among other things, an impedance detection circuit, method, and integrated circuit, comprising a ramp-up current generation circuit and an impedance determining circuit, wherein the ramp-up current generation circuit is configured to input a ramp-up current including n breaks to a port of a device where the ramp-up current generation circuit is disposed, to which port an external device is connected, and wherein the impedance determining circuit is configured to detect an impedance of the external device in each break time period of the ramp-up current input by the ramp-up current generation circuit until the impedance of the external device is acquired by detection in the last break time period of the n breaks.