Efficient screening procedures for the control of defectivity are vital to limit early failures, particularly in critical automotive applications. Traditional strategies based on burn-in and in-line tests are able to provide the required level of reliability, but they are expensive and time consuming. This paper presents a novel built-in circuitry to screen out gate oxide and crystalrelated defects in Lateral Diffused MOS transistors. The proposed technique is based on an embedded circuitry that includes control logic, high-voltage generation, and leakage current monitoring. The concept and the advantages of the proposed screening procedure are described in detail and demonstrated experimentally in conjunction with the integration of a test chip.Index Terms-Built-in self-test, burn-in, crystal defects, gate oxide reliability, gate stress test (GST).