Patent ID: 6847909

Claim:
A method of testing an electrical device to determine a range of combinations of values of first and second parameters for which the electrical device functions properly, the method comprising: testing the electrical device using a combination of values of the first and second parameters corresponding to a selected operating point comprising an origin of an R, θ polar coordinate plane; if the electrical device is determined to function in a passing manner at the selected operating point, updating the value of the polar coordinate R by incrementing the value thereof by a predetermined amount ΔR; otherwise, updating the value of the polar coordinate R by decrementing the value thereof by ΔR; if the updated value of the polar coordinate R is determined to be beyond an edge of a defined plot region in the R, θ polar coordinate plane, updating the value of the polar coordinate θ by a predetermined amount Δθ; and identifying an operating point corresponding to at least one of the updated values of the polar coordinates R and θ.