Jiangsu Changjing Electronics MMBT3904T

The MMBT3904T is a standard NPN bipolar junction transistor (BJT) designed for general-purpose amplification and switching applications. It is packaged in a small surface-mount package, making it suitable for space-constrained applications in electronic circuits. Functions: - Amplification: The MMBT3904T can amplify current signals, making it suitable for use in audio amplifiers and signal processing circuits. - Switching: It can act as a switch, controlling the flow of current in circuits by turning on (saturation) or off (cut-off) depending on the input signal. - Signal Modulation: It is also used in various signal processing applications, including modulation of radio frequencies. Applications: - Consumer Electronics: Used in audio devices, televisions, radios, and other consumer electronics for signal amplification and switching. - Communication Equipment: Common in circuits for telecommunication devices, where it amplifies signals or acts as a relay switch. - Automotive Electronics: Employed in automotive applications, including sensor signal processing and control units. - Industrial Control Systems: Utilized in automated systems for switching operations or amplifying sensor signals. - General Purpose: It's widely used in hobbyist projects and prototyping due to its versatility and availability. Alternative Parts: Some alternatives to the MMBT3904T include: - BC547: Another general-purpose NPN transistor with similar specifications. - 2N3904: A classic NPN transistor that can also serve as an alternative in various applications. - S8050: An NPN transistor that is sometimes used as an alternative, depending on the circuit requirements. Embedded Modules: Embedded modules utilizing the MMBT3904T may not be specific to this transistor but can be found in various development boards or modules that include amplification or switching circuits. Look for: - Microcontroller Development Boards: Boards with integrated NPN transistor stages for output driving, such as Arduino or Raspberry Pi interfaces. - Audio Amplifier Modules: Small amplifier circuits that might incorporate MMBT3904T for boosting audio signals. - Control Interface Modules: Modules for controlling motors or relays using the transistor as a switching element. Related Q&A 1. Q: What is the maximum collector current for the MMBT3904T? A: The maximum collector current (Ic) for the MMBT3904T typically is around 200 mA. 2. Q: Can the MMBT3904T be used for high-frequency applications? A: Yes, the MMBT3904T can be used in high-frequency applications, though it is primarily suited for general-purpose use. Its transition frequency (f_T) is usually around 250 MHz. 3. Q: What is the typical gain (h_FE) of the MMBT3904T? A: The typical DC current gain (h_FE) for the MMBT3904T is around 100 to 300, depending on the collector current and other conditions. 4. Q: Is the MMBT3904T suitable for driving relays? A: Yes, the MMBT3904T can be used to drive small relays, but it's essential to ensure that the current requirements of the relay do not exceed the maximum collector current of the transistor. 5. Q: What is the difference between the MMBT3904T and a MOSFET? A: The MMBT3904T is a bipolar junction transistor (BJT), which conducts when a current is applied to the base, while a MOSFET (metal-oxide-semiconductor field-effect transistor) conducts current based on voltage applied to the gate. This leads to differences in efficiency, switching speed, and input impedance.