onsemi 2N7000RLRAG N-Channel MOSFET: Datasheet, Pinout, and Application Circuits

The onsemi 2N7000RLRAG is a widely used and highly reliable N-channel enhancement-mode MOSFET. This small-signal transistor is a cornerstone in countless electronic designs, prized for its ability to be driven directly from logic-level signals like those from microcontrollers and other ICs. Its primary function is to act as a low-side switch, controlling power to a load with a simple digital on/off signal.

This article provides a detailed overview of its datasheet specifications, pinout configuration, and common application circuits.

Datasheet Overview and Key Specifications

The datasheet for the 2N7000RLRAG outlines its electrical characteristics and absolute maximum ratings, which are critical for ensuring safe and reliable operation in any circuit design.

Absolute Maximum Ratings:

Drain-Source Voltage (V_DS): 60 V

Gate-Source Voltage (V_GS): ±20 V

Continuous Drain Current (I_D): 200 mA

Total Power Dissipation: 350 mW

Key Electrical Characteristics (T_A = 25°C):

Gate Threshold Voltage (V_GS(th)): 0.8 V – 3.0 V. This low threshold is what makes it compatible with 3.3V and 5V logic circuits.

Drain-Source On-Resistance (R_DS(on)): Typically 5.0 Ω at V_GS = 10 V, I_D = 50 mA. This resistance determines the voltage drop and power loss when the MOSFET is fully turned on.

Input Capacitance (C_iss): 50 pF (typical). This low capacitance allows for very fast switching speeds.

Pinout Configuration

The 2N7000RLRAG is offered in the ubiquitous SOT-23 surface-mount package. The pinout, when viewed with the flat side facing you, is as follows:

Pin 1 (Left): Gate (G) – The control pin. Voltage applied here relative to the Source controls the flow of current between Drain and Source.

Pin 2 (Middle): Source (S) – Typically connected to ground in low-side switch configurations.

Pin 3 (Right): Drain (D) – Connected to the load that is being switched.

Correctly identifying these pins is essential to avoid damaging the component during circuit assembly.

Application Circuits

The 2N7000RLRAG's simplicity and effectiveness make it ideal for a variety of switching applications.

1. Basic Low-Side Switch

This is the most common application. A microcontroller GPIO pin is connected to the Gate through a current-limiting resistor (e.g., 100Ω). The load (e.g., an LED, relay, or small motor) is connected between the positive supply voltage (V_CC) and the MOSFET's Drain pin. The Source is connected to ground. When the microcontroller outputs a logic HIGH (3.3V or 5V), the MOSFET turns on, completing the circuit and powering the load. A pull-down resistor (e.g., 10kΩ) from the Gate to ground is often added to ensure the MOSFET turns off reliably when the GPIO is in a high-impedance state.

2. Driving a Relay Coil

MOSFETs are perfect for driving inductive loads like relay coils. In this circuit, a flyback diode (or freewheeling diode) is absolutely critical. It is placed in reverse bias across the relay coil (anode to Drain, cathode to V_CC). This diode provides a path for the current from the collapsing magnetic field when the MOSFET turns off, protecting the transistor from damaging voltage spikes.

3. Logic Level Converter

While not its primary function, a single 2N7000 can be configured as a simple unidirectional logic level shifter. It can effectively translate a signal from a lower voltage (e.g., 3.3V) to a higher voltage (e.g., 5V) for communication between devices operating on different logic levels.

ICGOODFIND: The onsemi 2N7000RLRAG remains a fundamental component in the engineer's toolkit. Its robust performance, logic-level compatibility, and cost-effectiveness solidify its status as a go-to solution for low-power switching, load driving, and general-purpose amplification tasks across consumer electronics, industrial controls, and hobbyist projects.

Keywords:

1. Logic-Level MOSFET

2. Low-Side Switch

3. SOT-23 Package

4. Enhancement-Mode

5. Application Circuits