1. Rated Current (Io) - US2DA-TP: 2A - ESH1D-E3/61T: 1A - The ESH1D has half the current capability of the US2DA-TP. If used directly in the original design under 2A or near-2A conditions, the diode will be overloaded, leading to excessive heating, reduced long-term reliability, or even failure. This is the primary limiting factor for substitution. 2. Reverse Recovery Time (trr) - US2DA-TP: 50 ns - ESH1D-E3/61T: 25 ns - The ESH1D exhibits faster recovery, which can reduce switching losses and noise in high-frequency switching circuits (e.g., CCM PFC, hard-switching topologies). However, if the circuit relies on specific recovery characteristics (e.g., soft recovery), compatibility must be verified. 3. Reverse Leakage Current (Ir) - US2DA-TP: 5 µA @200V - ESH1D-E3/61T: 1 µA @200V - The ESH1D has lower leakage current, resulting in reduced power dissipation under high voltage or high temperature conditions. This is beneficial for high-efficiency or low-power designs. 4. Maximum Junction Temperature (Tj) - US2DA-TP: 150°C - ESH1D-E3/61T: 175°C - The ESH1D offers superior high-temperature tolerance, providing greater reliability margin under poor thermal conditions. However, due to its lower current rating, this advantage may not be fully realized in practice. Note: Both devices share the same package (DO-214AC/SMA) and voltage rating (200V). However, the current rating is the decisive factor for substitution feasibility. The actual operating current and thermal conditions must be verified first. If substitution is necessary, it is recommended only when the circuit current is ≤0.5A and after thermal design validation.