Patent ID: 7224633

Claim:
An eFuse system comprising: a reference cell further comprising: a reference resistance further comprising a series connected resistor and an unblown first eFuse; and a first circuitry configured to produce a reference current, when suitable voltage supplies are coupled to the circuitry, that flows through the reference resistance producing a reference voltage between a first end of the reference resistance and a second end of the reference resistance; an eFuse cell comprising: a second eFuse having a first resistance greater than the reference resistance if the second eFuse is blown and a second resistance less than the reference resistance if the second eFuse is unblown; and a second circuitry configured to produce, when the suitable voltage supplies are coupled to the second circuitry, a mirrored copy of the reference current that flows through the second eFuse in the eFuse cell producing an eFuse cell voltage output between a first end of the second eFuse and a second end of the second eFuse; and a comparator having a first input coupled to the reference voltage and a second input coupled to the eFuse cell voltage output, the comparator, when supplied by a suitable comparator voltage supply, is configured to output a first logical level if the eFuse cell voltage output is greater than the reference voltage and a second logical level if the eFuse cell voltage output is less than the reference voltage.