Robust Built-in Defect-Detection for Low Drop-Out Regulators using Digital Mismatch Injection
Marampally Saikiran, Mona Ganji, Degang Chen
Abstract
The number of electronic components in mission-critical applications is increasing rapidly and, with the dawn of electric vehicles, this increase is expected to accelerate in the near future. As functional safety (FuSa) is of utmost importance in these applications, the increasing demand for integrated circuits with zero defective parts per million (DPPM) is pressing the chip industry to achieve high defect coverage. In this paper, simple digital Design for Test (DfT) techniques are presented to detect defects in Low Drop-Out Regulators (LDO). The proposed method uses digital mismatch injection and digital-like detectors to detect various defects in an LDO. The digital nature of the proposed method can help reduce the test cost by avoiding expensive and time-consuming analog testing circuitry. Using spice simulations, we show that our method can detect up to 97.5% of the defects providing high defect-coverage. Additionally, as our injectors and detectors are simple in nature, they are not only area-efficient and easy-to-design but also easily scalable. Furthermore, in this work, we also introduce a simple and robust dual-threshold detector that can be used to monitor faults in biasing circuits.