Patent ID: 7940499

Claim:
An integrated circuit comprising: a plurality of pads; a first current protection structure of a first type including a first diode and a second diode, the first current protection structure coupled to a first pad of the plurality of pads such that when a first set of one or more voltage conditions is present at the first pad, the first current protection structure activates to discharge current from or charge current to the first pad, the first set of one or more voltage conditions including a condition of the voltage exceeding a positive trigger voltage wherein at least a selectively conductive region of the first current protection structure is formed on the semiconductor substrate to be radially symmetric around the pad of the plurality of pads such that for a radial line extending outwards from a center of the pad a distance from the center of the pad to where the line intersects an outer edge of the pad has a ratio to a distance from the center of the pad to where the line intersects the perimeter of the selectively conductive region wherein the ratio is approximately constant as the line is rotated in a circle about the center of the pad; a second current protection structure of a second type different than the first type, the second current protection structure including a third diode and a fourth diode wherein the second current protection device is coupled to a second pad of the plurality of pads such that when a second set of one or more voltage conditions is present at the second pad, the second current protection structure activates to discharge current from or charge current to the second pad; and a current discharge or charge path that serves to provide current to or draw current from both the first current protection structure if activated and the second current protection structure if activated.