BSS123LT1G: Overview, Features, and Applications


The BSS123LT1G is an N-Channel Logic Level Enhancement Mode Field Effect Transistor (FET) manufactured by ON Semiconductor. As an integral component in various electronics, the BSS123LT1G is well-known for its specific attributes and practical applications.


  • Type: N-Channel Enhancement Mode Field Effect Transistor
  • Package: SOT-23
  • Manufacturer: ON Semiconductor
  • Polarity: It operates with a positive gate-to-source voltage to control the flow of current between the drain and source terminals.



  1. Enhancement Mode: Given its enhancement mode operation, it requires a positive gate-to-source voltage to enable conduction between the drain and source terminals.

  2. Logic Level Translation: The BSS123LT1G is designed for use in logic level shifting applications.

  3. Low Threshold Voltage: With a low threshold voltage, it can be effectively controlled with minimal gate voltage, making it suitable for low-power applications.

  4. Surface Mount Package: Housed in a SOT-23 package, it is optimized for surface mount applications, offering compactness and ease of assembly onto printed circuit boards.

  5. Low Input Capacitance: This attribute allows for easy and efficient integration in high-frequency applications by minimizing the capacitive loading of the driving circuit.

  6. Fast Switching Speed: Its swift switching characteristics enable efficient utilization in high-speed applications.


  1. Signal Switching: Commonly used in signal switching applications, particularly in low-power and portable devices due to its compact size and low power requirements.

  2. Level Shifting: The low threshold voltage makes it suitable for level shifting applications, particularly when interfacing signals between devices operating at different voltage levels.

  3. Load Switching: Utilized as a switch to control power supply to various sub-circuits, especially in battery-operated and low-power devices.

  4. Signal Amplification: In certain low-power and low-frequency applications, the BSS123LT1G can be used for signal amplification, leveraging its FET properties.

  5. Protection Circuits: Integrated into protection circuits to safeguard other components by controlling the flow of current based on specific conditions, such as overvoltage protection.

  6. Oscillator Circuits: The FET can be incorporated into oscillator and waveform generation circuits, particularly in low-power or small-scale integrated systems.

The BSS123LT1G FET is widely utilized in various digital and analog circuits due to its compact size, minimal control current requirements, and its ability to efficiently manage signal switching, level shifting, and power management within low-power and moderate-power electronics.