1. Current Rating & Surge Withstand - BTA312: 12A steady-state, 95A/105A surge; BTB08: 8A steady-state, 80A/84A surge. - The BTB08 offers less current margin. Its reliability risk is higher in applications operating near the original design's current limit or in high-surge scenarios (e.g., motor startup). 2. Trigger Characteristics - BTA312: Standard trigger (Igt ≤ 35mA, Vgt ≤ 1.5V); BTB08: Logic-level trigger (Igt ≤ 5mA, Vgt ≤ 1.3V). - The BTB08 can be driven directly by an MCU or digital circuit, simplifying the design. However, it is more susceptible to external noise, necessitating enhanced gate anti-interference measures (e.g., filtering). 3. Holding Current & Temperature Range - BTA312: Ih ≤ 35mA, only Tj max of 125°C specified; BTB08: Ih ≤ 10mA, temperature range -40°C to 125°C. - The BTB08 provides more reliable turn-off for low-current loads and is suitable for low-temperature environments. Note that the low Ih may increase the risk of spurious triggering in high-noise scenarios. 4. Manufacturer & Process Variations - Differences in wafer design and packaging between WeEn and ST may affect hidden parameters such as dynamic dv/dt capability and thermal resistance. - In high-frequency switching or inductive load applications, commutation performance and thermal behavior must be re-validated.