Taiwan Semiconductor

BC817-40

BC817-40 Description

The BC817-40 is an NPN bipolar junction transistor (BJT) manufactured by Taiwan Semiconductor Corporation, designed for high-performance switching and amplification applications. Packaged in a compact SOT-23 surface-mount form factor, it offers a collector-emitter voltage (Vce) rating of 45V and a maximum collector current (Ic) of 500mA, making it suitable for low-to-medium power circuits. With a transition frequency of 100MHz, it ensures efficient high-frequency operation, while its low Vce saturation voltage (700mV @ 50mA, 500mA) minimizes power loss in switching applications. The device is RoHS3 compliant and adheres to REACH and EAR99 regulations, ensuring environmental and export compliance.

BC817-40 Features

• High Current Gain (hFE): 250 (min) @ 100mA, 1V, ensuring robust signal amplification.
• Low Leakage Current: 100nA (ICBO) max, enhancing efficiency in precision circuits.
• Optimized for Surface Mounting: Tape & Reel (TR) packaging for automated assembly.
• Power Efficiency: 300mW max power dissipation with excellent thermal performance.
• Wide Operating Range: Suitable for 45V breakdown voltage and 500mA continuous current.
• High-Frequency Capability: 100MHz transition frequency ideal for RF and fast-switching applications.

BC817-40 Applications

The BC817-40 excels in:

• Switching Circuits: Relay drivers, LED drivers, and power management due to low saturation voltage.
• Amplification: Audio preamps, signal conditioning, and sensor interfaces leveraging high hFE.
• High-Speed Logic: Interface circuits, level shifters, and digital logic buffers (up to 100MHz).
• Portable Electronics: Battery-operated devices where low leakage and efficiency are critical.
• Automotive & Industrial Systems: Robust performance in harsh environments with stable DC characteristics.

Conclusion of BC817-40

The BC817-40 stands out as a versatile, high-performance NPN transistor with low power loss, high gain, and excellent frequency response. Its compact SOT-23 package and compliance with environmental standards make it ideal for modern electronics requiring reliability and efficiency. Whether used in switching, amplification, or high-speed logic, this transistor delivers consistent performance, making it a preferred choice for engineers in consumer, automotive, and industrial applications.