1. Current Rating & Package Thermal Resistance: The MURA260T3G's nominal current rating (2A) is double that of the FR105G (1A), primarily due to its larger die and SMA package. However, the DO-41 (through-hole) package typically offers superior thermal dissipation compared to a surface-mount SMA of a similar class. In high-reliability 1A continuous current applications, the FR105G may maintain a lower actual junction temperature due to better heat transfer (via its leads to the PCB or ambient air). Substitution necessitates re-evaluating the derating curves, especially in high-temperature environments. 2. Reverse Recovery Time: The MURA260T3G's trr (75 ns) is significantly faster than the FR105G's (250 ns). This difference is critical in high-frequency circuits like switching power supplies and PFC stages. Faster recovery reduces switching losses and reverse recovery current spikes, improving system efficiency and lowering EMI. However, the higher di/dt may exacerbate ringing in the circuit, requiring attention. 3. Package & Assembly Process: The FR105G is a through-hole (THT) device, while the MURA260T3G is surface-mount (SMT). This is a fundamental difference, requiring changes to PCB layout, soldering process (wave vs. reflow), and rework methods. Substitution effectively constitutes a design update, not a drop-in replacement. 4. Forward Voltage Drop: At comparable current densities, the MURA260T3G's Vf (1.45V @ 2A) suggests a newer or more optimized die technology. When normalized to the same 1A condition, its conduction loss may be lower than or equal to the FR105G's (1.3V @ 1A), potentially boosting efficiency. This should be confirmed by consulting detailed datasheet curves. 5. Cost & Application Positioning: The MURA260T3G carries a ~55% higher unit cost, reflecting its superior performance (faster speed, higher current) and SMT package pricing. If the original FR105G application does not utilize its full current or speed margin, substitution introduces unnecessary cost increase. This move is essentially a "performance upgrade," not a "cost-reduction replacement."