The 2N7002 is a widely used N-channel enhancement-mode Field Effect Transistor (MOSFET) packaged typically in a small SOT-23 form. It is designed for high-speed switching applications and is characterized by low gate charge and low on-resistance. This makes it particularly suitable for power management and load switching in portable and low-power devices.
2N7002 Pin Configuration
2N7002 Pin Configuration Diagram
The 2N7002 N-Channel MOSFET comes in a SOT-23 package and contains three terminals:
Gate (G): This is where you apply voltage to control the switching (on/off) of the MOSFET.
Drain (D): The terminal to which the current flows into, when the MOSFET is turned on.
Source (S): The terminal out of which the current flows, when the MOSFET is turned on.
Typically, looking at the flat side of the SOT-23 package with the leads pointing downward,
The left pin is the Source (S)
The middle pin is the Gate (G)
The right pin is the Drain (D)
Different manufacturers may have different pin configurations, so it's best to confirm from the datasheet. The datasheets of 2N7002 produced by different famous manufacturers are as follows:
Equivalent Circuit
2N7002 Equivalent Circuit Diagram
Features
The 2N7002 has many noteworthy features that make it a popular choice for a multitude of applications:
N-Channel MOSFET: The device is an N-Channel MOSFET, meaning it is controlled using a negative voltage and typically turned on by a positive gate-source voltage.
Low Voltage Operation: The 2N7002 can operate at low voltages, making it suitable for low voltage applications.
Low Gate-Source Threshold Voltage: It has a low threshold voltage (around 2.5V), which means it can be turned on with a relatively low gate voltage, making it suitable for signal switching applications.
Good Drain Current: There's a steady drain current of about 115mA at 25°C, which is adequate for many low power applications.
Capable of Withstanding Higher Temperatures: It can operate in temperatures ranging from -55°C to +150°C, thus making it reliable in diverse environmental conditions.
Compact SOT-23 Package: This device comes in a small 3-pin SOT-23 package, allowing it to fit in compact spaces and being suitable for surface mount applications.
Low On-Resistance: The On-Resistance (Rds On) of this MOSFET is relatively low (around 7.5 Ohms), which indicates less power loss when the device is in the on-state.
2N7002 Equivalent N-Channel MOSFET
For 2N7002 replacement or similar applications, MOSFETs such as BS170, BSS138, AO3400 (SOT-23) or AO3400A can be considered.
BS170
This N-Channel MOSFET has similar electrical characteristics to the 2N7002, but it comes in a TO-92 package, which is larger than the SOT-23 of the 2N7002.
BSS138
This one has similar electrical characteristics and also comes in a SOT-23 package, making it a drop-in replacement in most situations.
Remember, whenever you're looking for an equivalent part, such as a direct replacement in a circuit, you must compare the datasheets to ensure the substitute shares key parameters with the original. The most important factors to compare would typically include the maximum ratings for voltage (Vds, Vgs), current (Id, Idm), power dissipation (Pd), and specific electrical characteristics like the threshold voltage (Vgs(th)) and the on-resistance (Rds(on)).
Where to use 2N7002?
The 2N7002 is a versatile N-channel MOSFET that finds utility in a plethora of applications due to its small size, low cost, and good switching performance. It's primarily used where low power and/or signal level systems are involved, and can be effectively utilized in the following scenarios:
Low Voltage Applications: The 2N7002 is at ease with low voltage applications as its operational characteristics support it. The drain-source voltage of 60V and continuous drain current of 115mA point towards this fact.
Signal Switching Applications: The device is suitable for signal switching applications with a low threshold voltage of 2.5V, which means it can be turned on with a relatively minimal voltage.
Power Management: The 2N7002 can be used for power management in portable devices and other small scale digital and analog circuits due to its low power dissipation.
Load Switching: The transistor can be effortlessly used for load switching in low power critical applications, again thanks to its low power dissipation.
Motor Driving: The 2N7002 MOSFET can be used in driving small motors.
Please note, though the 2N7002 is a general-purpose device apt for many applications, its usage is mainly constrained by the current rating. It cannot drive loads beyond its specified drain current capacity. Always remember to check the datasheet and ensure that the device satisfies the requirements of your specific application before implementing it in your design.
Outline Dimensions
The dimensions of 2N7002 are as follows:
