BSS138 ON Semiconductor MOSFET N-CH 50V 220MA SOT23-3


The BSS138 is an N-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) manufactured by ON Semiconductor. Here are the key specifications and details about this component:


  • Manufacturer: ON Semiconductor
  • Model: BSS138
  • Type: N-Channel MOSFET
  • Voltage Rating: 50V
  • Current Rating: 220mA
  • Package: SOT-23-3 (Small Outline Transistor - 3 leads)
  • DataSheet

    BSS138 PDF

Key Features:

  1. N-Channel MOSFET: The BSS138 is an N-channel MOSFET, where current flows from the drain (D) to the source (S) when a sufficient voltage is applied at the gate (G).

  2. Voltage Rating (50V): This MOSFET can handle a maximum drain-source voltage of 50V.

  3. Current Rating (220mA): The maximum continuous drain current the MOSFET can handle is 220mA.

  4. Package (SOT-23-3): The SOT-23-3 package is compact and typically has three pins.

Main Specifications and Uses:

  • Switching Applications: N-channel MOSFETs like the BSS138 are commonly used for switching applications in electronic circuits.

  • Amplification: While MOSFETs are primarily used for switching, they can also be utilized for amplification in certain circuit configurations.

  • Voltage Regulation: MOSFETs can also be used in voltage regulation circuits, depending on the specific application requirements.

Working Principle:

  • When a voltage is applied at the gate terminal of the MOSFET, it creates an electric field that controls the conductivity between the source and drain terminals.

  • In an N-channel MOSFET like the BSS138, when a positive voltage is applied at the gate with respect to the source, it allows current to flow from the drain to the source.

Typical Applications:

  • Low-Power Switching Circuits: Suitable for low-power switching applications like signal routing or LED control circuits.

  • Level Shifting: Used for level shifting applications where input signals need to be translated to a higher or lower voltage.

  • Voltage-Level Translation: Helpful in converting logic level voltages within digital circuits.

  • Load Switching: Can be used to control the switching of loads in various electronic systems.

Implementation Considerations:

  • Gate Voltage: Ensure that the gate voltage does not exceed the maximum gate-source voltage rating to prevent damage.

  • Current Limitations: Adhere to the specified maximum drain current to prevent overloading the MOSFET.

  • Heat Dissipation: Consider heat dissipation requirements when operating the MOSFET at higher current levels.

  • Protection Circuitry: Implement protection measures like flyback diodes to safeguard the MOSFET from voltage spikes in inductive loads.

Before integrating the BSS138 N-channel MOSFET into your circuit design, it's important to consult the datasheet provided by ON Semiconductor for detailed specifications, electrical characteristics, and application guidelines to ensure proper and reliable operation within your specific electronic circuit.