An electrically programmable fuse, in the following also referred to as e-fuse, apparatus (100, 600, 800, 900, 1000, 1100), comprising: an e-fuse macro (102, 602), disposed In an integrated circuit (110, 610, 810, 910, 1010, 1110) and comprising a plurality of e-fuse units (202, 204, 206); characterised in that the electrically programmable fuse further comprises: a switch device (104, 604), disposed in the integrated circuit (110, 610, 810, 910, 1010, 1110) and having an output node coupled to the e-fuse units (202, 204, 206) and a first input node coupled to a first power source (108, 608, 808, 1008, 1108) which supplies a first reference voltage acting as a programming voltage of the e-fuse macro (102, 602), wherein the switch device (104, 604) connects the first power source (108, 608, 808, 1008, 1108) to the e-fuse units (202, 204, 206) when the e-fuse macro (102, 602) is operated under a programming mode; and a protection unit (107, 607), for preventing the switch aevice (104, 604) from connecting the first power source (108, 608, 808, 1008, 1108) to the e-fuse units (202, 204, 206) unless a correct password is inputted to the protection unit (107, 607) to unlock the programming protection; wherein when an electrical current resulting from the programming voltage at the output node flows through a specific e-fuse unit (202, 206) of the e-fuse macro (102, 602), a programmable fuse element (212, 216) of the specific e-fuse unit (202, 206) is blown. an e-fuse macro (102, 602), disposed In an integrated circuit (110, 610, 810, 910, 1010, 1110) and comprising a plurality of e-fuse units (202, 204, 206); characterised in that the electrically programmable fuse further comprises: a switch device (104, 604), disposed in the integrated circuit (110, 610, 810, 910, 1010, 1110) and having an output node coupled to the e-fuse units (202, 204, 206) and a first input node coupled to a first power source (108, 608, 808, 1008, 1108) which supplies a first reference voltage acting as a programming voltage of the e-fuse macro (102, 602), wherein the switch device (104, 604) connects the first power source (108, 608, 808, 1008, 1108) to the e-fuse units (202, 204, 206) when the e-fuse macro (102, 602) is operated under a programming mode; and a protection unit (107, 607), for preventing the switch aevice (104, 604) from connecting the first power source (108, 608, 808, 1008, 1108) to the e-fuse units (202, 204, 206) unless a correct password is inputted to the protection unit (107, 607) to unlock the programming protection; wherein when an electrical current resulting from the programming voltage at the output node flows through a specific e-fuse unit (202, 206) of the e-fuse macro (102, 602), a programmable fuse element (212, 216) of the specific e-fuse unit (202, 206) is blown. a switch device (104, 604), disposed in the integrated circuit (110, 610, 810, 910, 1010, 1110) and having an output node coupled to the e-fuse units (202, 204, 206) and a first input node coupled to a first power source (108, 608, 808, 1008, 1108) which supplies a first reference voltage acting as a programming voltage of the e-fuse macro (102, 602), wherein the switch device (104, 604) connects the first power source (108, 608, 808, 1008, 1108) to the e-fuse units (202, 204, 206) when the e-fuse macro (102, 602) is operated under a programming mode; and a protection unit (107, 607), for preventing the switch aevice (104, 604) from connecting the first power source (108, 608, 808, 1008, 1108) to the e-fuse units (202, 204, 206) unless a correct password is inputted to the protection unit (107, 607) to unlock the programming protection; wherein when an electrical current resulting from the programming voltage at the output node flows through a specific e-fuse unit (202, 206) of the e-fuse macro (102, 602), a programmable fuse element (212, 216) of the specific e-fuse unit (202, 206) is blown.