Fuse circuit using anti-fuse and method for searching for failed address in semiconductor memory

摘要

A fuse circuit comprises first and second electric fuses, a differential amplifier and a switch circuit. The first and second electric fuses have their respective current characteristics changed when a voltage of a predetermined level or more is applied thereto. The differential amplifier receives two voltage signals based on the current characteristics of the first and second electric fuses, outputs a predetermined voltage on the basis of a difference in voltage between the two voltage signals, and amplifies the predetermined voltage. The memory circuit stores an output from the differential amplifier. The switch circuit connects and disconnects the differential amplifier to and from the memory circuit.