BC857BWT1G Datasheet/PDFBC857BWT1G is a Surface Mount Plastic Small Signal NPN Transistor from NXP Semiconductors. It is a NPN silicon epitaxial planar transistor. This device is a subminiature size with more power and better performance, which is intended for use where space limitations are an important consideration. Its DC current gain ranges from 70 to 300. It comes in a very compact SOT-23 package. This device is designed for use in low voltage and medium power applications such as switching and amplifier applications.
The field of application of this transistor can be divided into four major groups:
- Switching applications;
- Amplifier applications;
- Motor control applications;
- Linear Voltage Regulator applications.
The primary applications of this transistor include switching in the consumer electronic industry, amplifier applications in automotive audio and video applications, motor control applications in consumer appliances and linear voltage regulator applications in computer and smart phone applications.
The working principle of this transistor can be understood by understanding the process of how a bipolar junction transistor (BJT) works. A BJT is basically a three-terminal device, with the two main terminals D and A being called the emitter and collector respectively. The third terminal E is called the base. A voltage applied to the base controls the current from the emitter to the collector. When a small current flows through the base, a larger current is allowed to flow from the emitter to the collector, thus amplifying the current.
When a signal is applied to the base of the BC857BWT1G, the signal is amplified by the transistor, and an amplified signal is generated at the collector terminal. This signal can be used to control the switching of other external devices, or to amplify weak signals. The BC857BWT1G has a DC current gain (Hfe) range of 70-300. This highlights the fact that the device’s switching and amplification capability depend heavily on the base current. As the base current increases, the current gain of the device increases as well, thus allowing more current to flow from the collector to the emitter.
Thus, the BC857BWT1G can be used for switching and amplifier applications which require a highly efficient and reliable transistor. As the transistor comes in a very compact SOT-23 package, it makes it ideal for use in applications which require miniaturization and where space is a premium. The wide current gain range offered by this device makes it an attractive option for those seeking a highly efficient and reliable switching and amplifier solution.