1. Reverse Voltage (Vr): The B350 is rated at 50V, while the SS34 is rated at 40V. If the operating voltage or voltage spikes in the original circuit approach 50V, substitution may pose a reliability risk. It is essential to ensure sufficient derating in the actual reverse voltage condition. 2. Forward Voltage Drop (Vf): The Vf of the SS34 (500mV) is notably lower than that of the B350 (700mV). Under a 3A load, the SS34 exhibits lower conduction loss (approximately 0.6W vs. 2.1W), which contributes to improved efficiency and reduced temperature rise. However, the lower Vf may slightly increase inrush current and should be considered. 3. Missing Capacitance Parameter: The SS34 does not provide junction capacitance data, whereas the B350 specifies 200pF. In high-frequency switching applications such as DC-DC converters, junction capacitance affects switching losses and noise. If the circuit is sensitive to parasitic parameters, high-frequency performance should be verified through measurement.