Electric fuse state detection circuit

Abstract

The invention discloses an electric fuse state detection circuit. The circuit comprises an electric fuse, a reference resistor, a first current supply, a second current supply, a third current supply,a switch and a comparison circuit; the comparison circuit generates an output signal according to a voltage value detected by a first input end and a voltage value detected by a second input end, theoutput signal is used for indicating whether the electric fuse is fused or not, wherein current values of the first current supply and the second current supply are referent currents, a current valueof a third current supply is a k-fold referent current, and the switch is closed when the electric fuse is in a test mode. When the electric fuse is in the test mode, the electric fuse can be judgedto be fused when a resistance value of the electric fuse is larger than a resistance value of a (1+k)-fold reference current; therefore, more strict conditions can be provided in the test mode so as to verify whether or not the electric fuse is fused, and therefore it is guaranteed that when a user uses the electric fuse obtained after testing and screening, whether or not the electric fuse is fused can be accurately and reliably judged.

Description

technical field [0001] The present invention relates to the technical field of semiconductor integrated circuits, and more particularly, to an electric fuse state detection circuit. Background technique [0002] Electrical fuse or electrically programmable fuse (electrically programmable fuse, eFUSE) is a one-time programmable memory widely used in integrated circuits, which can be used to modify the identification, function and electrical characteristics of integrated circuits, such as, In the manufacturing process of the chip, when testing the chip, electric fuses can be used to adjust the chip parameters, and the parameters that deviate from a certain range outside the chip specification range are corrected back to the expected range. In practical applications, according to the resistance value of the electric fuse, the state of the electric fuse is sensed to determine whether the electric fuse has been blown, that is, whether the electric fuse is a blown fuse (programmed...

AI Technical Summary

Problems solved by technology

Therefore, when a blown electric fuse with an abnormal resistance value is sensed, it will be difficult to discern the state of the blown electric fuse, that is, a blown electric fuse with an abnormal resistance value may be regarded as an unblown electric fuse, As a result, the detection results of the electric fuse are inaccurate

In this way, when the user uses a blown electric fuse with an abnormal resistance value, that is, when the electric fuse is in the user mode, it means that some characteristics or functions of the product using the electric fuse will change under different usage situations, Even errors or exceptions occur

Images