1. Current Rating & Conduction Loss – SDUR6060W: 60A, Vf = 2.0V @ 60A – VS-EPH3006LHN3: 30A, Vf = 2.65V @ 30A – The latter not only reduces current capacity by 50%, but also exhibits higher conduction loss (P = Vf × I) at the same current level. If the original load current approaches 60A, substitution will lead to thermal overstress and failure. Even when operated below 30A, its higher Vf increases power dissipation, requiring recalculation of thermal margins. 2. Dynamic Characteristics & Applicable Frequency – Reverse recovery time (trr): 26ns (Vishay) vs. 50ns (SMC) – The Vishay device switches faster, which can reduce switching losses in high-frequency applications such as PFC or inverters. However, this advantage is limited by its lower current capability. If the original circuit operates at high frequency, replacement may prevent full performance utilization due to insufficient current rating. 3. Reliability Standards & Application Scenarios – VS-EPH3006LHN3 is AEC-Q101 qualified, with junction temperature range –55°C to 175°C – SDUR6060W is industrial grade, with maximum junction temperature of 150°C – The Vishay part suits automotive or other high-reliability, high-temperature environments. In standard industrial applications, this advantage may not be realized. Note also its TO-247AD package (same pinout as TO-247AC, but with isolated thermal tab); insulation requirements must be verified during installation. 4. Leakage Current & High-Temperature Stability – Reverse leakage current: 30µA @ 600V (Vishay) vs. 100µA (SMC) – The Vishay device offers lower leakage under high temperature and voltage, which can improve system efficiency and high-temperature stability. However, in high-current designs, this is generally not a critical factor. Recommendation: If the actual operating current is ≤20A and switching performance or automotive qualification is prioritized, derated substitution may be considered after re-running thermal simulations. Otherwise, select an alternative with a matching current rating.