IRLZ44N Logic-Level MOSFET for 12V and 24V Power Switching

ElecSuppliers Part Number GuideAug 22, 2026

IRLZ44N is a popular N-channel power MOSFET designed for low-voltage switching applications. It combines a 55V drain-source voltage rating with high current capability and logic-level gate drive characteristics, making it useful in battery-powered equipment, DC motor control, power switching and embedded hardware.

The device is available in a TO-220 package and is often selected when a power MOSFET needs to be controlled directly or with a relatively low gate-drive voltage.

IRLZ44N Key Specifications

IRLZ44N has a maximum drain-source voltage of 55V and a maximum continuous drain current rating of 47A under specified thermal conditions.

Its maximum power dissipation is 83W with the appropriate thermal conditions.

The device is characterized as a logic-level MOSFET. Its maximum on-resistance is specified at both 4.5V and 10V gate drive, with values of 35mΩ and 22mΩ respectively under the specified test conditions.

The maximum junction temperature is 175°C.

These specifications make IRLZ44N particularly suitable for low-voltage power switching where conduction losses and gate-drive requirements are important design considerations.

IRLZ44N Logic-Level Gate Drive

The term "logic-level" is one of the main reasons IRLZ44N is widely used in embedded electronics.

A conventional power MOSFET may require a relatively high gate voltage to achieve its specified low on-resistance. IRLZ44N is characterized at a lower gate voltage, including 4.5V.

This makes it easier to interface with microcontrollers and digital control circuits.

However, logic-level does not mean that every 3.3V microcontroller will automatically drive the MOSFET to its lowest possible resistance. The actual gate voltage and required load current should always be considered together.

IRLZ44N at 5V Gate Drive

IRLZ44N is commonly considered for 5V gate-drive circuits.

When the gate is driven around 5V, the MOSFET can provide substantially lower conduction resistance than it would with a partially enhanced gate.

This is useful in circuits where a microcontroller or logic device controls a power load through a MOSFET.

For higher-current applications, the designer should still evaluate gate charge, switching frequency, PCB resistance and thermal performance rather than selecting the MOSFET solely from its current rating.

IRLZ44N at 3.3V

IRLZ44N is sometimes used with 3.3V microcontrollers, but this requires more careful evaluation.

The gate threshold voltage should not be confused with the voltage required to achieve low on-resistance.

A MOSFET can begin conducting at a relatively low gate voltage while still having considerably higher resistance than its specified value.

If a 3.3V MCU is expected to switch a high-current load, the designer should check the IRLZ44N electrical characteristics at the actual gate voltage.

A dedicated MOSFET gate driver may be a better solution when the load current or switching performance is demanding.

IRLZ44N Pinout

IRLZ44N uses a three-terminal power MOSFET configuration.

The standard pin arrangement is:

Pin 1 — Gate

Pin 2 — Drain

Pin 3 — Source

The metal tab of the TO-220 package is electrically connected to the drain.

This is important when mounting the MOSFET to a heatsink or metal chassis because electrical isolation may be required.

The pinout should be checked carefully when replacing IRLZ44N with another MOSFET because not every device in a similar package uses the same lead arrangement.

IRLZ44N for DC Motor Control

DC motor switching is one of the practical applications for IRLZ44N.

A microcontroller can control the MOSFET gate while the MOSFET switches the motor's supply current.

For PWM motor control, the MOSFET is repeatedly switched between its conducting and non-conducting states.

The switching frequency, gate-drive strength and motor current all affect MOSFET losses.

Because a motor is an inductive load, an appropriate flyback path and protection circuit should also be included.

IRLZ44N for LED Power Switching

IRLZ44N can be used as a low-side switch for LED lighting systems.

The microcontroller controls the gate while the MOSFET handles the current flowing through the LED load.

This arrangement can be useful for 12V LED strips and other low-voltage lighting systems.

For PWM brightness control, the MOSFET can be switched at a suitable frequency to regulate the average power delivered to the LEDs.

The actual load current should be checked before selecting the MOSFET and heatsink configuration.

IRLZ44N for Battery Applications

IRLZ44N can be used in low-voltage battery-powered systems where a MOSFET is required for load switching or power-path control.

12V battery systems are a common example.

The 55V drain-source rating provides voltage headroom for many 12V applications, but the complete circuit should still account for voltage spikes and transients.

For higher-voltage battery packs, the 55V rating may not provide sufficient margin.

In such cases, a MOSFET with a higher voltage rating should be considered.

IRLZ44N for Inverters

IRLZ44N can also be used in low-voltage inverter circuits.

Multiple MOSFETs may be arranged in half-bridge or full-bridge configurations to switch current through a transformer, motor or other load.

In these applications, gate-drive timing becomes much more important.

Dead time, switching losses, gate charge and thermal management must be considered when several MOSFETs are switching at high frequency.

IRLZ44N is particularly suited to relatively low-frequency power switching rather than high-frequency power conversion designs.

IRLZ44N RDS(on)

RDS(on) is one of the most important parameters when evaluating IRLZ44N.

The lower the on-resistance, the lower the conduction loss for a given current.

The conduction loss can be approximated by:

P = I² × RDS(on)

This means that a small increase in current can cause a much larger increase in conduction loss.

For example, doubling the current results in approximately four times the conduction loss if the resistance remains constant.

This is why PCB layout and thermal design become increasingly important as load current increases.

IRLZ44N Gate Charge

Gate charge is another important parameter when IRLZ44N is used for switching.

The gate behaves differently from a simple resistive input. The driver must supply and remove charge every time the MOSFET switches.

At higher switching frequencies, the repeated charging and discharging of the gate can contribute to overall power loss.

IRLZ44N has a relatively substantial gate charge compared with many newer small-signal MOSFETs.

For low-frequency switching, this may not be a major issue. For high-frequency PWM or switching converters, it should be included in the design calculations.

IRLZ44N Thermal Design

Although IRLZ44N has a high current rating, the actual usable current depends strongly on temperature and thermal conditions.

The MOSFET generates heat from both conduction and switching losses.

At higher temperatures, the device has less thermal margin.

A heatsink may therefore be required when the MOSFET is continuously carrying substantial current.

PCB copper area can also contribute to heat dissipation, particularly when the MOSFET is mounted directly on a suitable board layout.

The current rating should never be interpreted as a guaranteed operating current under every application condition.

IRLZ44N Switching Frequency

IRLZ44N is optimized for relatively low-frequency switching applications.

This makes it useful for DC motor control, load switching, lighting and similar applications.

When used at higher frequencies, the gate charge and switching transition times become increasingly important.

A MOSFET that performs well as a low-frequency power switch is not necessarily the best choice for a high-frequency SMPS.

For high-speed switching converters, a newer MOSFET with lower gate charge and optimized switching characteristics may provide better overall efficiency.

IRLZ44N Replacement

When searching for an IRLZ44N replacement, engineers should compare more than the 55V voltage rating and current specification.

Important parameters include:

Drain-source voltage, on-resistance at the actual gate voltage, gate charge, continuous current, package, pinout and thermal characteristics.

The replacement should also be evaluated according to the switching frequency and gate-driver voltage.

A MOSFET with a lower nominal RDS(on) may not necessarily perform better if that resistance is specified at a gate voltage higher than the available driver voltage.

IRLZ44N Alternative Selection

For a 12V or 24V switching circuit, a suitable alternative should provide sufficient voltage margin above the normal supply voltage.

For high-current applications, low RDS(on) is important.

For PWM and higher-frequency switching, gate charge and switching characteristics become more significant.

For a 3.3V MCU design, the most important question is whether the alternative provides appropriate on-resistance at the actual gate voltage.

Therefore, an IRLZ44N alternative should be selected based on the complete operating conditions rather than simply finding another N-channel MOSFET with a similar current rating.

IRLZ44N Package

IRLZ44N is supplied in a TO-220 package, which is convenient for through-hole assembly and applications requiring significant thermal dissipation.

The package also makes it relatively easy to attach a heatsink.

However, the metal tab is connected to the drain, so the electrical relationship between the heatsink and MOSFET must be considered during mechanical design.

If several MOSFETs share one heatsink, electrical isolation may be necessary.

IRLZ44N Applications

IRLZ44N can be considered for:

DC motor controllers, 12V and 24V load switching, LED lighting, battery-powered equipment, low-voltage inverters, solenoid drivers, relay control, robotics and embedded power-control circuits.

Its combination of logic-level operation, high current capability and a common TO-220 package makes it particularly recognizable in low-voltage power electronics.

Choosing IRLZ44N

IRLZ44N is most useful when a design needs a rugged N-channel MOSFET for relatively low-voltage power switching and the available gate-drive voltage is compatible with its electrical characteristics.

For a simple 12V load switch, motor controller or LED power circuit, it can be a practical choice.

For high-frequency converters, very low-voltage systems or demanding 3.3V gate-drive applications, newer MOSFET technologies may provide better efficiency.

The correct selection should always be based on the actual drain voltage, load current, gate voltage, switching frequency and thermal conditions rather than the headline current rating alone.