Infineon IRF640NSTRLPBF N-Channel Power MOSFET: Datasheet, Pinout, and Application Circuits

The Infineon IRF640NSTRLPBF is a classic N-channel power MOSFET that has established itself as a reliable workhorse in power electronics. Designed using advanced process technology, this transistor offers a robust combination of high current handling, low on-state resistance, and fast switching speeds, making it suitable for a wide array of applications from power supplies to motor control.

Datasheet Overview and Key Specifications

The datasheet for the IRF640NSTRLPBF reveals its core electrical characteristics, which are critical for design engineers. Key specifications include:

Drain-Source Voltage (V_DS): 200V, making it suitable for off-line switchers and other medium-voltage applications.

Continuous Drain Current (I_D): 18A at a case temperature of 25°C, indicating its strong current-carrying capability.

On-State Resistance (R_DS(on)): A maximum of 0.15Ω at I_D = 9A and V_GS = 10V. This low resistance is crucial for minimizing conduction losses and improving overall system efficiency.

Gate Threshold Voltage (V_GS(th)): Typically between 2-4V, defining the turn-on point of the device.

Fast Switching Speed: This feature is essential for high-frequency switching applications, helping to reduce switching losses.

Pinout Configuration

The IRF640NSTRLPBF is offered in the industry-standard TO-262 package (also known as TO-220FullPack or D2PAK). Its pinout is straightforward:

1. Gate (G): This is the control pin. A voltage applied between the Gate and Source terminals activates the MOSFET.

2. Drain (D): The main current flows into the MOSFET through this pin. It is connected to the tab of the TO-262 package.

3. Source (S): The main current flows out of the MOSFET through this pin, completing the circuit.

Application Circuits

The versatility of the IRF640NSTRLPBF allows it to be used in numerous circuit configurations. Two common examples are:

1. Low-Side Switch:

This is one of the most frequent uses of an N-channel MOSFET. The load (e.g., a DC motor, relay, or lamp) is connected between the Drain pin and the positive supply voltage (V_DD). The Source pin is connected directly to ground. A microcontroller or gate driver circuit provides the control signal to the Gate pin, switching the load on and off. A gate resistor (e.g., 10-100Ω) is often used to dampen oscillations and control the switching speed.

2. PWM Motor Speed Controller:

In this application, the IRF640NSTRLPBF acts as the main switching element. A Pulse Width Modulation (PWM) signal from a microcontroller is fed to the Gate pin through a gate driver IC (or a simple BJT buffer for slower speeds). The varying duty cycle of the PWM signal effectively controls the average power delivered to the motor, thereby regulating its speed. A flyback diode is critical across the motor's terminals to protect the MOSFET from voltage spikes caused by the motor's inductive kickback when it is switched off.

Conclusion and Summary by ICGOODFIND

ICGOODFIND: The Infineon IRF640NSTRLPBF remains a highly effective and economical solution for a broad spectrum of power switching tasks. Its strong balance of 200V voltage rating, 18A current capacity, and low R_DS(on) ensures reliable performance in demanding environments like DC-DC converters, motor drives, and power inverters. Designers continue to value its robustness and ease of implementation in both low-side and high-side (with a proper gate driver) switch configurations.

Keywords:

1. Power Switching

2. RDS(on)

3. TO-262 Package

4. Motor Control

5. Low-Side Switch