1. Current and Power Handling Capability: The BUK964R7-80E has significantly higher continuous current (120A) and maximum power dissipation (324W) compared to the STH145N8F7-2AG (90A, 200W). The BUK964R7-80E likely requires a larger physical footprint and more robust thermal design. A direct replacement may not leverage its performance advantages due to space or thermal constraints and could alter the thermal resistance due to mounting differences. 2. Different Reference Points for Gate Drive Voltage (Vgs) and On-Resistance (Rds(on)): The ST part's drive voltage and Rds(on) specifications are based on a Vgs of 10V, whereas the Nexperia part's nominal drive voltage is specified as 5V (though its Rds(on) is also tested at 10V). This indicates different intended drive voltage ranges: the ST part is optimized for 10V or higher to ensure optimal performance, while the Nexperia part achieves its specified low Rds(on) at a nominal 5V Vgs, placing lower voltage demands on the drive circuit. Direct substitution could stress the Nexperia device's gate under the original 10V drive (its maximum Vgs is only ±10V vs. ±20V for the ST part) or leave the ST device under-driven if the circuit only supplies 5V. 3. Switching Performance and Gate Charge (Qg): Although their Qg values are similar (~96nC vs. 92nC), the test conditions differ (10V vs. 5V). More critically, the Nexperia device's input capacitance (Ciss) is over 2.4 times that of the ST device (15340 pF vs. 6340 pF). With the same gate drive circuit, driving the BUK964R7-80E would require higher peak current and result in longer switching times. This could lead to significantly increased switching losses, reduced efficiency, and potential overloading or thermal issues in the existing gate driver. 4. Threshold Voltage (Vgs(th)): The Nexperia part's maximum threshold voltage (2.1V) is much lower than the ST part's (4.5V). This makes the Nexperia device easier to turn on but also more susceptible to noise-induced false triggering, imposing stricter requirements on circuit noise immunity and PCB layout. Summary: Despite similar packages and automotive-grade ratings, the BUK964R7-80E,118 is a higher-performance MOSFET with distinctly different drive requirements and switching characteristics. A direct replacement would necessitate re-evaluation and potential modification of the gate drive circuit, thermal design, and PCB layout, followed by comprehensive system testing. Without the resources to perform this validation, direct substitution is not recommended.