Standard cell library characterization for setting current limits for I/sub DDQ/ testing

Industry needs to move from a separate step of design for test to solving test issues as an integral part of the design process. The linking of design and test is also needed for I/sub DDQ/ testing, which is required for high quality products. A key issue is how to set the I/sub DDQ/ current limit to detect defective parts without rejecting defect-free parts. Increasing design efforts for accurate standard cell library characterization, especially with respect to power provide the answer. This paper describes a method for setting the I/sub DDQ/ limit based upon cell library characterization. Additionally, the method for iterating in on the final values is reviewed and contrasted with the benefits of the new method.