A small circuit element that can be irreversibly changed from being non-conducting to being conducting with ~100 Ohm. Anti-fuse-based FPGAs are thus non-volatile and can be programmed only once (see OTP).

An antifuse is an electrical device that performs the opposite function to a fuse. Whereas a fuse starts with a low resistance and is designed to permanently break an electrically conductive path (typically when the current through the path exceeds a specified limit), an antifuse starts with a high resistance and is designed to permanently create an electrically conductive path (typically when the voltage across the antifuse exceeds a certain level).