1. Voltage & Technology Platform: The TK17A80W is an 800V device based on DTMOSIV technology, while the IPA60R280P6 is a 600V CoolMOS P6. The TK17A80W offers a higher voltage margin, making it suitable for topologies with higher input voltages or greater voltage stress (e.g., PFC, half-bridge). However, its Super Junction process is optimized more for high-voltage performance rather than achieving the absolute lowest on-state resistance at lower frequencies. 2. Current Rating & Test Conditions: The TK17A80W's 17A rating is specified at ambient temperature (Ta), whereas the IPA60R280P6's 13.8A rating is based on case temperature (Tc). Consequently, the actual continuous current capability difference under equivalent thermal conditions is much smaller than the nominal ratings suggest. Furthermore, the TK17A80W's Rds(on) of 290mΩ is measured at 8.5A, compared to 280mΩ at 5.2A for the IPA60R280P6. This indicates the TK17A80W may maintain better conduction performance at higher operating currents. 3. Dynamic (Switching) Performance: The TK17A80W exhibits significantly higher gate charge (Qg: 32nC) and input capacitance (Ciss: 2050pF) compared to the IPA60R280P6 (Qg: 25.5nC; Ciss: 1190pF). Driving the TK17A80W requires higher peak drive current or results in longer switching times, leading to increased switching losses. This is particularly detrimental in high-frequency applications (e.g., >100kHz), where it can reduce system efficiency and increase heat generation. The drive circuit must be re-evaluated to ensure it can supply sufficient peak current. 4. Thermal Resistance & Heat Sink Design: The TK17A80W has a higher nominal power dissipation (45W vs. 32W), though the package thermal resistances are not directly comparable. Its higher power rating likely stems from a larger die area. In practice, if the original heat sink is retained, the TK17A80W may operate at a higher junction temperature due to its increased switching losses, necessitating verification of thermal design margins. 5. Cost: The TK17A80W carries a unit cost approximately 83% higher. In cost-sensitive designs, the advantage of increased voltage margin may not justify the replacement. Summary: Substitution is feasible but requires careful scrutiny of switching frequency, drive capability, and thermal conditions. An upgrade to the TK17A80W is justifiable if the original design operates near the 600V limit or requires higher reliability margins. However, if the original design operates at high frequency with ample voltage headroom, the substitution may lead to reduced efficiency and increased cost.