1. Reverse Voltage Rating & Leakage Current - MBR20H150CTG: 150 V, leakage 50 µA @ 150 V - STPS20170CT: 170 V, leakage 15 µA @ 170 V - The STPS20170CT provides higher blocking voltage and lower leakage current (tested at a higher voltage). In scenarios with significant input voltage variation or where a larger safety margin is needed, the STPS20170CT delivers more stable blocking characteristics, making it particularly suitable for secondary‑side rectification in power‑factor‑correction (PFC) or flyback switching power supplies. 2. Forward Voltage Drop (Vf) - MBR20H150CTG: 680 mV @ 10 A - STPS20170CT: 900 mV @ 10 A - The Vf of the STPS20170CT is notably higher, resulting in an approximate 32% increase in conduction loss (ΔVf ≈ 220 mV). At 10 A, each diode dissipates about 2.2 W more, imposing stricter demands on thermal design and potentially affecting overall system efficiency and temperature rise. 3. Junction Temperature Range - MBR20H150CTG: -20°C to 150°C - STPS20170CT: Maximum junction temperature 175°C - The STPS20170CT allows a higher peak operating temperature, offering better thermal headroom in high‑ambient or transient overload conditions. This advantage, however, is only realized with appropriate thermal design. 4. Technology Series Background - The MBR20H150CTG belongs to onsemi’s SWITCHMODE™ series, optimized for high‑frequency switching power supplies and typically offering superior dynamic characteristics (e.g., soft‑recovery performance). - The STPS20170CT is not marked as part of a special series and is likely a general‑purpose industrial‑grade product. - In high‑end switching power supplies (e.g., >100 kHz) or applications with stringent EMI requirements, the MBR20H150CTG may exhibit better performance regarding high‑frequency switching noise and reverse‑recovery oscillation. The STPS20170CT is adequate for conventional frequency operation. Supplementary Replacement Verification Recommendations: 1. Verify that the actual peak operating voltage remains below 150 V; otherwise, the higher voltage rating of the STPS20170CT becomes relevant. 2. Calculate the increase in conduction loss and assess its impact on system efficiency and heat‑sink sizing. 3. If used in high‑frequency switching applications, practical measurement of switching noise and temperature rise after replacement is recommended.