1. Product Grade and Certification (Core Difference): PDZ7.5B-AU_R1_000A1 is explicitly marked “Grade: Automotive” and carries the “Qualification: AEC-Q101” certification. PDZ7.5B_R1_00001 lacks such marking and certification. The AU version is specifically designed and qualified for automotive electronics applications. AEC-Q101 is a stress test qualification standard for discrete semiconductor devices established by the Automotive Electronics Council. It requires the device to pass a series of rigorous reliability tests, such as wider temperature cycling, higher-temperature reverse-bias lifetime testing, and strict process consistency controls. This indicates that the AU version meets the high demands of the automotive industry in terms of long-term reliability, lot-to-lot consistency, and stability under extreme temperature and vibration conditions. The price premium primarily stems from this certification and the associated production quality control costs. 2. Application Scenarios and Design Considerations: For standard applications such as consumer electronics or general industrial equipment, the two are interchangeable. However, using the AU version in such cases constitutes “over-design” and introduces unnecessary material cost. Conversely, for automotive electronics (e.g., ECUs, power management, sensor protection) or any industrial or medical equipment requiring high reliability, the AEC-Q101-qualified AU version must be selected. This difference directly impacts product design qualification, reliability targets, and ultimately market access—particularly the mandatory requirements for entering the automotive supply chain.