2n3904 – npn transistor

The 2n3904 is a widely used npn silicon transistor designed for low-power, general-purpose applications. It works as a current-controlled device, where a small base current efficiently controls a larger current between the collector and emitter. Known for its fast switching speed, stable performance, and compact size, the 2n3904 is an excellent choice for signal processing, digital switching, and small-signal amplification. Its reliability makes it suitable for both educational projects and professional electronic designs.

Key features
• Npn silicon transistor design
• Low-power, general-purpose operation
• High current gain (hfe: 100–300)
• Fast switching response
• Collector-emitter voltage rating up to 40 v
• Maximum collector current of 200 ma
• Low noise performance for clean signal handling
• Compact to-92 package for easy pcb mounting
• Suitable for audio and rf applications

Typical applications
• Signal amplification circuits
• Switching and driver circuits
• Logic and control systems
• Led and relay drivers
• Oscillators and timer circuits