on November 1th 5,008

BSS138 MOSFET Explained: Key Features and Technical Overview

The BSS138 MOSFET is a compact, efficient component used in low-voltage and low-current applications. This guide covers its main features, uses, and specifications, helping you understand why it’s a popular choice in electronics.

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BSS138 MOSFET Overview

BSS138 is an N-Channel MOSFET, specially designed for low-voltage and low-current uses. Known for its efficiency, this component keeps on-state resistance low, which helps in reducing energy loss. Its compact, reliable structure makes it a good choice for fast switching tasks. The BSS138 MOSFET is often found in small devices that need smooth current control, like servo motors and power gate drivers. In these applications, it ensures consistent performance and durability, handling small-scale switching jobs without compromising speed or quality.

BSS138 Pin Configuration

Pin Number	Pin Name	Description
1	Source	Current flows out through Source
2	Gate	Controls the biasing of the MOSFET
3	Drain	Current flows in through Drain

BSS138 CAD Model

BSS138 Symbol

BSS138 Footprint

BSS138 3D Model

BSS138 Technical Specifications

Technical specifications, features, characteristics, and components with comparable specifications of ON Semiconductor BSS138

Type	Parameter
Lifecycle Status	ACTIVE (Last Updated: 6 days ago)
Factory Lead Time	8 Weeks
Contact Plating	Tin
Mount	Surface Mount
Mounting Type	Surface Mount
Package / Case	TO-236-3, SC-59, SOT-23-3
Number of Pins	3
Supplier Device Package	SOT-23-3
Weight	30mg
Current - Continuous Drain (Id) @ 25°C	220mA Ta
Drive Voltage (Max Rds On, Min Rds On)	4.5V, 10V
Number of Elements	1
Power Dissipation (Max)	360mW Ta
Turn Off Delay Time	20 ns
Published	2002
Operating Temperature	-55°C~150°C TJ
Packaging	Tape & Reel (TR)
Part Status	Active
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Termination	SMD/SMT
Resistance	6Ω
Max Operating Temperature	150°C
Min Operating Temperature	-55°C
Voltage - Rated DC	50V
Current Rating	220mA
Base Part Number	BSS138
Element Configuration	Single
Power Dissipation	360mW
Turn On Delay Time	2.5 ns
FET Type	N-Channel
Rds On (Max) @ Id, Vgs	3.5Ω @ 220mA, 10V
Vgs(th) (Max) @ Id	1.5V @ 1mA
Input Capacitance (Ciss) (Max) @ Vds	27pF @ 25V
Gate Charge (Qg) (Max) @ Vgs	2.4nC @ 10V
Rise Time	9ns
Drain to Source Voltage (Vdss)	50V
Vgs (Max)	±20V
Fall Time (Typ)	9 ns
Continuous Drain Current (ID)	220mA
Threshold Voltage	1.3V
Gate to Source Voltage (Vgs)	20V
Drain to Source Breakdown Voltage	50V
Dual Supply Voltage	50V
Input Capacitance	27pF
Drain to Source Resistance	3.5Ω
Rds On Max	3.5Ω
Nominal Vgs	1.3V
Width	1.3mm
Height	930μm
Length	2.92mm
REACH SVHC	No SVHC
Radiation Hardening	No
RoHS Status	ROHS3 Compliant
Lead Free	Lead Free

Key Features of BSS138

Low On-State Resistance

The BSS138 MOSFET stands out for its low on-state resistance, reducing power loss during operation. With an on-state resistance of 3.5Ω at a gate-source voltage of 10 V and 6.0Ω at 4.5 V, this MOSFET supports smooth, efficient energy flow, ideal for applications where minimizing power loss is essential.

High-Density Cell Design

Built with a high-density cell design, the BSS138 ensures reliable performance even in compact spaces. This design enhances its ability to conduct current efficiently, making it suitable for tight, space-constrained projects while maintaining reliable, steady performance.

Compact SOT-23 Package

The BSS138 is encased in a standard SOT-23 surface mount package, offering both durability and a space-saving form factor. This compact package allows for easy integration into designs where space is limited, helping create streamlined, efficient circuits.

Equivalent Components to BSS138

• NTR4003

• 2N7002

• FDC666

• FDC558

• BS170

• 2N7000

Applications of BSS138

Low-Voltage Switching

The BSS138 MOSFET is effective for low-voltage switching applications, allowing it to perform well in systems that require controlled, reliable switching at low power levels. It can handle these tasks efficiently, making it an excellent fit for power management circuits that don’t require high current.

Logic Level Shifters

This MOSFET is useful in logic level shifting, where it adjusts voltage levels between different parts of a circuit. This feature makes it ideal for projects needing voltage compatibility between components, ensuring that signals are transmitted smoothly without any interruptions.

DC-DC Converters

The BSS138 also finds its place in DC-DC converters, where it aids in converting one DC voltage level to another. This application is common in portable electronics that rely on stable power conversion to keep multiple components running efficiently.

eMobility and Battery-Powered Devices

Thanks to its energy efficiency and low resistance, the BSS138 is well-suited for battery-powered applications, such as eMobility devices. It helps in conserving battery life, ensuring that devices can operate longer on a single charge without unnecessary power loss.

Power Management Systems

In power management systems, the BSS138 plays a valuable role by helping manage the flow of current within electronic devices. Its low on-state resistance and efficient switching ability make it ideal for these systems, ensuring minimal energy waste and steady current regulation.

BSS138 Package Details

Dim	Min	Max	Typ
A	0.37	0.51	0.4
B	1.2	1.4	1.3
C	2.3	2.5	2.4
D	0.89	1.03	0.915
F	0.45	0.6	0.535
G	1.78	2.05	1.83
H	2.8	3	2.9
J	0.013	0.1	0.05
K	0.903	1.1	1
K1	-	0.4	-
L	0.45	0.61	0.55
M	0.085	0.18	0.11
α	0°	8°	-

Datasheet PDF

BSS138 Datasheet:

BSS138.pdf