BSS138K

The BSS138K is a N-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) manufactured by ON Semiconductor. It is designed for low-voltage applications and is commonly used in switching and amplification circuits. Here’s a detailed description of its key features and specifications:

Package and Physical Characteristics:

• Package Type: The BSS138K is typically available in a surface-mount package, specifically the SOT-23 package, which is compact and suitable for space-constrained applications.
• Dimensions: The SOT-23 package generally measures approximately 2.9 mm x 1.3 mm x 1.1 mm, making it ideal for modern electronic devices where board space is at a premium.

Electrical Characteristics:

• Drain-Source Voltage (V_DS): The maximum drain-source voltage is rated at 50V, allowing it to handle a wide range of applications without risk of breakdown.
• Gate-Source Voltage (V_GS): The maximum gate-source voltage is typically ±20V, providing flexibility in control signal levels.
• Continuous Drain Current (I_D): The BSS138K can handle a continuous drain current of up to 220 mA at a temperature of 25°C, making it suitable for low to moderate power applications.
• R_DS(on): The on-resistance (R_DS(on)) is low, typically around 3.5 ohms at V_GS = 10V, which helps minimize power loss during operation and improves efficiency.

Performance Characteristics:

• Threshold Voltage (V_GS(th)): The gate threshold voltage is in the range of 0.8V to 1.5V, which means it begins to conduct at relatively low gate voltages, making it suitable for logic-level applications.
• Switching Speed: The BSS138K features fast switching capabilities, which is beneficial for high-frequency applications. The rise and fall times are typically in the nanosecond range, allowing for efficient operation in digital circuits.

Applications:

• Switching Applications: The BSS138K is widely used in low-side switching applications, where it can control loads such as motors, LEDs, and relays.
• Level Shifting: It is often employed in level shifting applications, particularly in interfacing between different voltage domains in digital circuits.
• Signal Amplification: The device can also be used in analog applications for signal amplification due to its low noise characteristics.

Thermal Characteristics:

• Junction-to-ambient Thermal Resistance (RθJA): The thermal resistance is typically around 250°C/W, which indicates how well the device can dissipate heat. Proper thermal management is essential to ensure reliable operation, especially under high load conditions.

Conclusion:

The BSS138K from ON Semiconductor is a versatile and reliable N-channel MOSFET that is well-suited for a variety of electronic applications. Its compact size, low on-resistance, and ability to operate at low gate voltages make it a popular choice among engineers and designers for both consumer and industrial electronics.