IRLZ44N 47A 55V Logic Level N-Channel MOSFET

The IRLZ44N is a high-current N-channel logic-level MOSFET intended for electronic switching and power-control applications. It allows a low-voltage control signal to switch a substantially higher-current load, making it especially useful in microcontroller-controlled systems.

The device features a 55V maximum drain-source voltage and a specified continuous drain current of up to 47A at 25°C, provided that the MOSFET is operated within its thermal and electrical limits. Actual usable current depends heavily on heatsinking, PCB design, ambient temperature, switching conditions, and load characteristics.

Its low RDS(on) helps reduce conduction losses when the MOSFET is adequately driven. The TO-220 package also makes it convenient to attach an external heatsink for applications involving significant current or power dissipation.

Features

• N-channel enhancement-mode MOSFET
• Logic-level gate design
• 55V drain-source voltage rating
• 47A specified continuous drain current under appropriate conditions
• Low RDS(on) for reduced conduction losses
• Suitable for PWM switching
• Fast switching characteristics
• TO-220AB through-hole package
• Suitable for microcontroller-controlled switching
• Useful for high-current DC load control
• Suitable for heatsink mounting in higher-power applications

Pin Configuration

For the standard TO-220 package, viewed from the front with the markings facing you and leads pointing downward:

1. Gate (G) – Control terminal
2. Drain (D) – Main current terminal
3. Source (S) – Main current terminal

Always verify the pinout against the specific manufacturer's datasheet before installation, as package configurations can vary between related components.

Applications

• Arduino-controlled DC loads
• DC motor control
• Robotics projects
• PWM motor speed control
• LED dimming and lighting control
• Solenoid switching
• Relay switching
• Heater control
• DC-DC converter circuits
• Battery-powered equipment
• Automotive electronics
• Power switching circuits
• DIY electronic projects

How It Works

The IRLZ44N uses the voltage between its Gate and Source terminals to control current flowing between the Drain and Source.

When the gate is driven sufficiently positive relative to the source, the MOSFET turns on and provides a low-resistance path between drain and source. When the gate voltage is removed, the MOSFET turns off.

For a typical low-side switching circuit, connect the Source to Ground, connect the Load between the positive supply and Drain, and drive the Gate from the controller.

For inductive loads such as motors, solenoids, and relays, use an appropriate flyback diode or other suitable transient protection across the load.

Microcontroller Use

The IRLZ44N is commonly described as a logic-level MOSFET, making it suitable for control from microcontrollers. However, the gate threshold voltage should not be interpreted as the voltage at which the MOSFET is fully enhanced.

For low-voltage microcontroller applications, verify the manufacturer's RDS(on) specification at the actual gate-drive voltage being used. A 5V gate drive is generally much more appropriate for this device than relying on the threshold voltage alone.

A typical gate-control circuit may include:

• A series gate resistor around 10Ω–100Ω to reduce ringing and limit transient gate current.
• A 10kΩ pull-down resistor between Gate and Source to keep the MOSFET off while the controller is starting up.
• A suitable flyback diode when switching inductive loads.

Important Notes

• The 47A current rating is not a guarantee that the MOSFET can safely carry 47A in every application.
• High-current operation requires proper heatsinking, PCB copper area, wiring, thermal management, and appropriate operating conditions.
• Do not use the gate threshold voltage as the recommended full-on drive voltage.
• Verify RDS(on) at your actual gate-drive voltage.
• Keep the Gate-Source voltage within the specified maximum limit.
• Never exceed the 55V drain-source voltage rating.
• Use suitable protection when switching motors, relays, solenoids, or other inductive loads.
• A heatsink may be required for high-current or high-power applications.
• Avoid connecting the MOSFET directly to high-voltage AC mains unless the complete circuit is specifically designed and rated for that application.
• Always verify the exact component datasheet when designing safety-critical or high-power circuits.

Package Includes

• 1 × IRLZ44N 47A 55V Logic Level N-Channel MOSFET