Patent ID: 7521993

Claim:
A method of operation, comprising: propagating a first current through a first current mirror formed of at least two devices disposed on a substrate, wherein, when a stress is present, a behavior of at least one of the at least two devices is dependent on a direction in which the at least one of the at least two devices forming the first current mirror is disposed on the substrate; propagating a second current through a second current mirror formed of at least two devices disposed on a substrate, wherein, when the stress is applied, a behavior of at least one of the at least two devices forming the second current mirror is dependent on a direction in which the at least one of the at least two devices forming the second current mirror is disposed on the substrate, wherein the at least one of the at least two devices forming the first current mirror and the at least one of the at least two devices forming the second current mirror are disposed in different orientations with respect to each other; measuring the first current propagated through the first current mirror; measuring the second current propagated through the second current mirror; and calculating a ratio of a difference between the first measured current and the second measured current to a sum of the first measured current and the second measured current, wherein the ratio is an amplified function of a stress signal indicating magnitude of the stress present, wherein the magnitude of the stress present is capable of calculation based on the different orientations of the devices.