Abstract: An integrated circuit (IC) applicable to performing system protection through dynamic voltage change may include a monitoring circuit, at least one power voltage generation circuit and a voltage adjustment circuit. The monitoring circuit monitors at least one security checking result of a security engine to determine whether at least one security event occurs. The at least one power voltage generation circuit generates at least one internal power voltage within the IC according to at least one input voltage received from outside of the IC, to provide the internal power voltage to at least one internal component of the IC. In response to occurrence of the at least one security event, the voltage adjustment circuit controls the at least one power voltage generation circuit to dynamically adjust the at least one internal power voltage, to control the internal power voltage randomly exceed predetermined voltage range thereof, thereby performing the system protection.