1. Reverse Voltage (Vr) and Leakage Current (Ir) Characteristics: Difference: The B230LA-E3/61T has a rated reverse voltage of 30V, with its leakage current specification (500µA) measured at 30V. The B220A-13-F has a rated reverse voltage of 20V, with its leakage current specification (500µA) measured at 20V. This is not merely a difference in voltage rating; the more critical distinction lies in reliability under electrical stress. At the same 20V reverse voltage, the B230LA experiences only 67% of its rated stress. Its actual leakage current is likely far below the specified value, resulting in more reliable operation and lower thermal dissipation. If the B220A operates near 20V, it is at its rated limit. Its leakage current will increase significantly (potentially exceeding 500µA), leading to reduced efficiency, increased temperature rise, and higher long-term reliability risk. If the original design leverages the 30V rating to handle voltage spikes, the 20V-rated B220A carries a risk of breakdown. 2. Clarity of Junction Capacitance Parameter (Cj): Difference: The B220A-13-F explicitly provides a junction capacitance parameter (200pF @ 4V, 1MHz), while this data is unavailable for the B230LA-E3/61T. Junction capacitance directly impacts diode performance in high-frequency switching circuits (e.g., SMPS rectification, high-frequency signal detection). Excessive capacitance increases switching losses and degrades signal edges. The B220A provides a key dynamic parameter for evaluation, whereas this parameter is unknown for the B230LA. In high-frequency applications, using the B230LA carries a hidden risk of circuit performance degradation (e.g., reduced efficiency, increased noise) due to potential capacitance mismatch. In this aspect, selecting the B220A offers greater predictability. Conclusion: The core deciding factor is voltage stress. Derating is an engineering principle. Replacing a 30V device with a 20V one significantly reduces the design safety margin, necessitating careful evaluation of actual voltage waveforms and spikes. Secondly, in high-speed applications, the B220A with its known capacitance parameter may provide greater design certainty.