SMMBT3904LT1G ON Semiconductor TRANS NPN 40V 200MA SOT23-3


The SMMBT3904LT1G is an NPN (Negative-Positive-Negative) Bipolar Junction Transistor (BJT) manufactured by ON Semiconductor. Here are the key specifications and details about this component:


  • Manufacturer: ON Semiconductor
  • Model: SMMBT3904LT1G
  • Type: NPN Bipolar Junction Transistor
  • Voltage Rating: 40V
  • Current Rating: 200mA
  • Package: SOT-23-3 (Small Outline Transistor - 3 leads)
  • DataSheet


Key Features:

  1. NPN Bipolar Junction Transistor (BJT): The SMMBT3904LT1G is an NPN transistor, a type of BJT where current flows from the collector to the emitter when a voltage is applied to the base.

  2. Voltage Rating (40V): This transistor can withstand a maximum collector-emitter voltage of 40V.

  3. Current Rating (200mA): The maximum collector current the transistor can handle continuously is 200mA.

  4. Package (SOT-23-3): The SOT-23-3 package is a small surface-mount package with three pins.

Main Specifications and Uses:

  • Amplification: NPN BJTs like the SMMBT3904LT1G are commonly used in amplification circuits due to their high current gain characteristics.

  • Switching Applications: Often utilized for signal switching in digital and analog circuits.

  • Signal Processing: Used in various signal processing applications that require amplification or switching.

  • Voltage Regulation: Can be part of voltage regulation and reference circuits in electronic systems.

Working Principle:

  • In an NPN BJT, applying a positive voltage at the base relative to the emitter causes current to flow from the collector to the emitter, allowing the BJT to act as an amplifier or switch.

Typical Applications:

  • Amplifiers: Commonly employed in audio and RF amplifiers due to their high current gain.

  • Digital Logic Circuits: Used in digital circuits when amplification or switching is required.

  • Waveform Generators: Found in signal generators and waveform shaping circuits.

  • Voltage Comparators: Utilized in voltage comparator circuits for comparing different voltage levels.

Implementation Considerations:

  • Base Resistor: Implement a base resistor to limit the current into the base of the transistor and prevent damage.

  • Maximum Ratings: Operate the transistor within the specified voltage and current limits to ensure reliability.

  • Heat Dissipation: Consider heat dissipation requirements when operating at higher current levels to prevent overheating.

  • Load Matching: Match the transistor to the load requirements to ensure proper functionality and longevity.

Before integrating the SMMBT3904LT1G NPN BJT into your circuit design, it's essential to refer to ON Semiconductor's datasheet for detailed specifications, pinout information, application notes, and usage guidelines to ensure optimal performance and reliability within your specific electronic circuit.