1. Current Rating Difference – The 25CTQ045-1 does not specify a forward average current rating, but its Vf test condition of 15A implies it is designed for higher current applications. – The VS-MBR1545CT-1-M3 is explicitly rated for 7.5A, indicating its practical current capability may be only half that of the former. – If the original design operates near 15A, substitution could result in overheating and failure. 2. Forward Voltage Drop Characteristics – 25CTQ045-1: Vf = 710 mV @ 15A – VS-MBR1545CT-1-M3: Vf = 570 mV @ 7.5A – At the same current level, the 25CTQ045-1 may exhibit lower conduction losses, though this must be evaluated alongside die area and thermal design. Substitution could alter system efficiency and thermal distribution. 3. Reverse Leakage Current Order-of-Magnitude Difference – 25CTQ045-1: 1 mA @ 45V – VS-MBR1545CT-1-M3: 100 µA @ 45V – The VS-MBR1545CT-1-M3 offers superior leakage control, making it suitable for static power-sensitive applications. However, the higher leakage of the 25CTQ045-1 may reflect structural optimization for high-frequency/high-current operation; direct replacement could affect high-temperature stability. 4. Extended Operating Temperature Range – The VS-MBR1545CT-1-M3 supports –65°C, compared to –55°C for the 25CTQ045-1. – In extreme low-temperature environments, the VS-MBR1545CT-1-M3 provides more reliable startup and operational performance.