1. Qualification Difference: The MMBZ15VALDBZRQ1 is explicitly marked with Grade: Automotive and is AEC-Q101 qualified, whereas the MMBZ15VALDBZR lacks this certification. The former has undergone automotive-grade reliability testing (e.g., moisture sensitivity, temperature cycling, ESD protection) and is suitable for automotive environments. The latter is only guaranteed for general commercial/industrial performance. 2. Supply Chain and Reliability Grade: The production process, testing standards, and lot traceability for the Q1 version are more stringent, ensuring long-term stability under extreme automotive conditions such as temperature and vibration. The non-Q1 version may utilize the same wafer but does not undergo automotive-grade screening, resulting in a potentially higher latent failure rate. 3. Root Cause of Price Difference: The higher price of the Q1 version ($0.41 vs. $0.36) primarily reflects the cost of qualification and reliability assurance, not differences in electrical parameters. In non-critical applications, the non-Q1 version can reduce costs, but this comes with an associated reliability risk.