2N2221

The 2N2221 is a versatile NPN bipolar junction transistor engineered for general-purpose low-power amplification and switching applications. Its robust construction and reliable performance make it a staple component in many electronic circuits where dependable switching, modest power handling and frequency response are required. Maximum collector current of 800 mA supports a wide range of moderate current applications. Collector-emitter voltage rating of 40 V ensures suitability across varied voltage environments. Transition frequency near 300 MHz enables efficient operation at high switching speeds. Gain bandwidth product around 100–300 provides reliable amplification performance. TO-18 metal can package enhances durability and thermal performance. Compared to other transistors in its class, the 2N2221 offers a balanced combination of current handling and switching speed, outperforming older models with lower frequency limits or reduced current capacity. This balance contributes to its continued popularity among hobbyists, educators and professional designers who require a proven, readily available device. The transistor's construction optimizes charge carrier flow to minimize power loss during switching and reduce noise generation in amplification tasks. These attributes make the 2N2221 suitable for a broad range of analog and digital circuits, including general switching duties, signal amplification and educational circuit builds where stable, repeatable behavior is important. When selecting a transistor for a design, consider the 2N2221 for applications that demand moderate current capability, respectable frequency response and the mechanical and thermal benefits of a metal can package.