Project – 2N3904 NPN General Purpose Transistor

The 2N3904 NPN BJT is a general-purpose transistor we employ mostly in Switching operations. It has a high DC Current Gain of 300 and the maximum current that can flow through the collector pin is 200mA. The maximum base current it can take is 5mA and in a fully saturated state, you can connect a load up to 200mA to this transistor. In Saturation Region, the typical voltage allowed across the Collector-Emitter (V­CE) or Collector-Base (VCB) could be 40V and 60V respectively. In the cut-off region, the voltage across the base-emitter junction is 600mV. Its applications include driver modules like relay module, LED module, commonly used in TV and other appliances.

Specifications

• Bi-Polar NPN Transistor
• Maximum DC Current Gain (h_FE) is 300
• Continuous Collector current (IC) is 200mA
• Base- Emitter Voltage (VBE) is 6V
• Collector-Emitter Voltage (VCE) is 40V
• Collector-Base Voltage (VCB) is 60V
• Available in To-92 Package

As discussed above, it can be used as a switch if operated in the cutoff and saturation region. It can also act as an Amplifier when operating in an Active region. It can amplify power voltage and current in different configurations but common emitter configuration is most common. You can check out other NPN transistor 2N2222 NPN transistor, BC547 NPN transistor, etc.