STP200NF04 40V N-Channel Power MOSFET

ElecSuppliers Part Number GuideAug 22, 2026

STP200NF04 is an N-channel power MOSFET designed for high-current switching applications. With a 40 V drain-source voltage rating and very low on-state resistance, the device is intended for power circuits where low conduction losses and high current capability are important.

The MOSFET belongs to the STMicroelectronics STP series and uses a through-hole power package, making it suitable for applications that require robust PCB mounting and effective thermal management.

STP200NF04 Key Specifications

STP200NF04 is rated for a maximum drain-source voltage of 40 V.

Its drain current capability is designed for high-current switching applications, while its low on-state resistance helps reduce conduction losses when the MOSFET is fully turned on.

The device uses an N-channel structure and is controlled through a conventional insulated gate.

The relatively low voltage rating makes the MOSFET particularly suitable for low-voltage DC power systems rather than high-voltage mains switching.

40V N-Channel MOSFET

A 40 V MOSFET is commonly used in circuits operating from low-voltage DC power rails.

Typical systems include 12 V, 24 V and other low-voltage power architectures where switching transients remain within the MOSFET's voltage limits.

The 40 V rating provides a defined maximum drain-source voltage, but the actual circuit should be designed with sufficient margin because switching circuits can generate voltage spikes significantly above the nominal supply voltage.

Snubbers, TVS protection or other transient-suppression methods may be required depending on the application.

STP200NF04 Low On-Resistance

Low on-state resistance is one of the main advantages of STP200NF04.

When an N-channel MOSFET is fully enhanced, current flows between the drain and source with a relatively low resistance.

The conduction loss can be approximated using:

P = I² × RDS(on)

This means that even a small reduction in RDS(on) can significantly reduce power dissipation at high current.

For example, if a MOSFET carries 50 A, the conduction loss becomes highly dependent on its actual RDS(on) at the operating gate voltage and temperature.

For this reason, engineers should evaluate RDS(on) under the actual gate-drive and temperature conditions rather than using a typical value alone.

STP200NF04 High-Current Switching

STP200NF04 is designed for applications where substantial current needs to be switched electronically.

Compared with mechanical relays, a power MOSFET can switch much faster and can be controlled directly by a suitable gate-drive circuit.

This makes the device useful in DC motor controllers, switching regulators, battery-powered equipment and power-management systems.

However, high-current MOSFET applications require careful PCB design. The current path should have sufficiently low resistance and inductance to prevent excessive voltage drops and heating.

STP200NF04 Gate Drive

The MOSFET is controlled through its gate terminal.

When an appropriate gate-source voltage is applied, the MOSFET enters its low-resistance conduction state. Removing the gate drive turns the device off.

The gate is insulated from the main current path, so the steady-state gate current is very small. However, charging and discharging the gate capacitance requires current during switching.

This means the gate driver has an important influence on switching speed and power loss.

A weak gate driver can cause the MOSFET to spend more time in its linear region during switching, increasing switching losses.

STP200NF04 Applications

STP200NF04 can be used in a wide range of low-voltage power applications.

Typical applications include:

DC-DC converters

Motor control

Battery-powered equipment

Automotive power systems

Low-voltage switching regulators

Power distribution circuits

Battery protection circuits

The exact suitability depends on current level, switching frequency, thermal conditions and voltage transients.

STP200NF04 Motor Control

One potential application is low-voltage motor control.

In a DC motor controller, the MOSFET can act as a high-speed electronic switch that controls the power delivered to the motor.

Pulse-width modulation can be used to regulate the average motor voltage and therefore control speed or torque.

Because motors are inductive loads, switching them can generate voltage transients. A suitable flyback path or other protection circuit is therefore important.

The MOSFET's voltage rating should include sufficient margin for these switching events.

STP200NF04 in DC-DC Converters

STP200NF04 can also be used as the main switching element in low-voltage DC-DC converter circuits.

In a switching converter, the MOSFET repeatedly turns on and off at a controlled frequency. The switching action transfers energy through an inductor or transformer and allows the output voltage to be regulated efficiently.

For converter applications, both conduction loss and switching loss need to be considered.

Low RDS(on) helps reduce conduction loss, while gate charge, output capacitance and switching characteristics influence switching performance.

STP200NF04 Thermal Design

High-current MOSFETs can generate significant heat even when their on-state resistance is low.

The main conduction loss can be estimated using the MOSFET's RDS(on), but the resistance normally increases with junction temperature.

This creates a thermal feedback effect: higher temperature increases resistance, which can increase conduction loss.

The package, PCB copper area, heatsink and airflow therefore all influence the actual operating temperature.

For continuous high-current operation, thermal analysis should be performed using the worst-case ambient temperature and expected current.

STP200NF04 Package

STP200NF04 uses a through-hole power package designed for effective heat transfer to the PCB or an external heatsink.

Through-hole packages can provide strong mechanical attachment and are commonly used in power electronics where the component needs to dissipate substantial heat.

The mounting method should follow the package's thermal requirements.

If a heatsink is used, the electrical isolation requirements between the MOSFET tab and heatsink must also be considered.

STP200NF04 Replacement

When replacing STP200NF04, the first parameters to check are drain-source voltage, continuous drain current and RDS(on).

Gate-drive requirements are equally important. A replacement MOSFET with a similar voltage rating but substantially different gate charge may change switching losses and driver requirements.

Package dimensions and pin configuration should also be matched.

For high-current applications, the thermal characteristics of the replacement device can be just as important as its electrical specifications.

STP200NF04 Design Considerations

A low-voltage power MOSFET should not be selected solely according to its nominal voltage and current ratings.

Engineers should consider voltage transients, gate-drive voltage, RDS(on), gate charge, switching frequency, thermal resistance and PCB layout.

The 40 V rating also needs to be compared with the actual peak drain-source voltage generated by the circuit.

For inductive loads, additional transient protection may be necessary to keep the MOSFET within its safe operating limits.

STP200NF04 for Low-Voltage Power Switching

STP200NF04 is a 40 V N-channel power MOSFET intended for high-current, low-voltage switching applications.

Its low-resistance power-switching characteristics make it suitable for DC-DC conversion, motor control, battery systems and other power-management circuits.

For new designs, the MOSFET should be evaluated according to actual current, gate-drive voltage, switching frequency and thermal conditions. For replacement applications, matching the voltage rating, RDS(on), gate characteristics, package and pin configuration is essential.