STMicroelectronics

MD1802FX

MD1802FX Description

The MD1802FX from STMicroelectronics is a high-voltage NPN bipolar junction transistor (BJT) designed for demanding power applications. Encased in the ISOWATT218FX package, it offers a robust 700V collector-emitter breakdown voltage (V_CEO) and a 10A maximum collector current (I_C), making it suitable for high-power switching and amplification tasks. With a 57W maximum power dissipation and a 150°C maximum junction temperature (T_J), this transistor ensures reliable performance under extreme conditions. Its low collector cutoff current (200µA) and moderate DC current gain (h_FE ≥ 5.5 @ 5A, 5V) further enhance efficiency in high-voltage circuits.

MD1802FX Features

• High Voltage & Current Handling: 700V V_CEO and 10A I_C for power-intensive applications.
• Low Saturation Voltage: 1.5V max @ 1.25A base current and 5A collector current, reducing power losses.
• Thermally Robust: ISOWATT218FX package ensures effective heat dissipation, supporting 57W power dissipation.
• Compliance & Reliability: ROHS3 compliant, REACH unaffected, and MSL 1 (unlimited) for environmental and storage flexibility.
• Obsolete Status: While no longer in production, it remains a viable choice for legacy designs requiring high-voltage BJTs.

MD1802FX Applications

• Switching Power Supplies: Ideal for offline SMPS (switch-mode power supplies) due to high V_CEO and current capability.
• Motor Control: Suitable for driving high-voltage motors in industrial and automotive systems.
• Electronic Ballasts: Efficiently controls fluorescent and HID lamp ballasts.
• CRT Deflection Circuits: Historically used in cathode-ray tube (CRT) monitors and televisions.
• Industrial Inverters: Supports high-voltage DC-AC conversion in welding equipment and UPS systems.

Conclusion of MD1802FX

The MD1802FX stands out for its high-voltage tolerance, current robustness, and thermal stability, making it a reliable choice for legacy and specialized power electronics. Though obsolete, its ISOWATT218FX package and low saturation losses ensure continued relevance in repair, maintenance, or niche applications requiring 700V BJTs. Engineers seeking alternatives should consider modern equivalents but may still leverage this transistor’s proven performance in high-stress environments.