Apparatus and method for providing a reprogrammable electrically programmable fuse

Abstract

An apparatus and method for providing a reprogrammable electrically programmable fuse (eFuse) are provided. With the apparatus and method, a pair of eFuses are provided coupled to programming current sources and sensing current sources. When the pair of eFuses is to be programmed, a first programming current is applied to a first eFuse to thereby increase the resistance of the first eFuse by an incremental amount. When the pair of eFuses is to be returned to an unprogrammed state, a second programming current source is applied to a second eFuse to thereby increase a resistance of the second eFuse to be greater than the resistance of the first eFuse. When the sensing current is applied to the eFuses, a difference in the resulting voltages across the eFuses is identified and used to indicate whether the reprogrammable eFuse is in a programmed state or unprogrammed state.

Description

BACKGROUND OF THE INVENTION [0001] 1. Technical Field [0002] The present invention relates generally to an improved integrated circuit device. More specifically, the present invention is directed to an apparatus and method for providing a reprogrammable electrical programmable fuse (eFuse). [0003]2. Description of Related Art [0004] An electrical programmable fuse (eFuse) is a simple circuit element that has one of two different states: blown or unblown. As is generally known in the art, the writing of data to eFuses involves the blowing of eFuses to represent a “1” and the leaving of eFuses in their default state, i.e. unblown, to represent a “0” value. In the unblown state, the eFuse enables an electrical contact while in the blown state, the electrical contact is severed. However, the opposite approach may be taken in the case of, for example, inverse eFuses in which blowing of the eFuse actually enables an electrical contact thereby representing a “0” with the default state repr...

AI Technical Summary

Benefits of technology

The present invention provides an electrically programmable fuse (eFuse) that can be reprogrammed after an initial programming. The eFuse has two differential signals that can be used to program it. The eFuse is calibrated to ensure accurate programming. The invention also provides a method for controlling the programming of the eFuse using switches. The reprogrammable eFuse can be used in various data processing devices such as integrated circuits, multi-chip packages, motherboards, gaming consoles, handheld computing devices, and non-portable computing devices.

Problems solved by technology

With efuses, if an imperfection is detected in the integrated circuit, the appropriate eFuses are tripped, i.e. blown.

If the technology detects that the chip is malfunctioning because individual circuits are running too fast or too slow, it can “throttle down” these circuits or speed them up by controlling appropriate local voltage.

In so doing, the eFuse can only be programmed once and cannot be reprogrammed.

Because of this limitation, eFuses, under the current technology, are not appropriate for use in applications where reprogrammability is required.

For example, eFuses cannot be used in electrically erasable programmable read only memory (EEPROM) applications, which typically require that the EEPROM be written to, read, and erased in a reprogrammable manner.

Images