How does IRF640 differ from IRF740?
07 October 2023
Ⅴ. IRF640 vs IRF740: Technical parameters
Ⅶ. IRF640 vs IRF740: Working principle
Ⅷ. IRF640 vs IRF740: Applications
Ⅸ. IRF640 vs IRF740: Pin configuration
Ⅹ. What are the application advantages of IRF640 and IRF740?
The IRF640 and IRF740 are both N-channel power MOSFETs used in electronic circuits for switching and amplification applications. While they have some similarities, there are also key differences between them. In this article, we will compare the IRF640 and IRF740.
Metal-Oxide Semiconductor Field Effect Transistor, referred to as MOSFET, MOS-FET or MOS FET. It is a field-effect transistor that can be widely used in analog circuits and digital circuits. MOSFETs can be divided into "N-type" and "P-type" according to the polarity of their channels (working carriers). They are usually also called NMOSFET (NMOS) and PMOSFET (PMOS).
MOSFET is a four-terminal device with Source, Gate, Drain and Body terminals. Typically, the body of a MOSFET is connected to the source terminal, creating a three-terminal device such as a field-effect transistor.
IRF640 is a general-purpose N-channel MOS field effect transistor. It has the characteristics of high conductivity, low leakage current and fast switching speed, and is widely used in various power amplifier circuits. The IRF640 belongs to Vishay's third generation Power MOSFETs. It provides designers with a powerful combination of fast switching, ruggedness, low on-resistance and high efficiency.
The maximum source-drain voltage of IRF640 reaches 200V, and the maximum drain current reaches 18A. It has the advantages of high voltage withstand, strong conduction capability, weak reverse leakage, and can be used repeatedly. At the same time, IRF640 has low on-resistance and high reverse breakdown voltage. These characteristics make it a popular power transistor. In terms of power control, IRF640 is often used in switching mode.
Replacement and equivalent：
• BUZ30A
• IRF640N
• STP19NB20
• YTA640
• 2SK891
IRF740 is an N-channel field effect transistor. It uses new low-charge Power MOSFET technology, and the gate charge is significantly lower than traditional MOSFETs. Utilizing new LCDMOS technology, its performance is enhanced without increasing cost, significantly simplifying gate drive requirements and saving overall system overhead. The IRF740 has a maximum drain current of 10 amps, a maximum drain-source voltage of 400 volts, a maximum power dissipation of 125 watts, and a drain-source on-resistance of 0.55 ohms. These parameters determine the application range and performance of IRF740 in the field of power control.
Replacement and equivalent：
• BUZ61A
• RFP7N35
• SIHF740-E3
• 2SK1400A
1. Features of IRF640
• Maximum continuous current (ID): 10 amps
• Maximum withstand voltage (VDS): 400V
• Blocking voltage (VGS(th)): Typically between 2 and 4 volts, this is the gate voltage at which the MOSFET begins to conduct.
2. Features of IRF740
• Low gate charge
• 100% avalanche tested
• Exceptional dvldt capability
• Very low intrinsic capacitances
1. Working principle of IRF640
When a positive voltage is applied to the gate, an electric field is formed between the gate and source, and this electric field affects the channel region. When the gate voltage is high enough (often called the gate threshold voltage), the electric field drives free electrons into the N-type channel, thereby forming a conductive channel in the channel, allowing current to flow from source to drain. When the gate voltage decreases or becomes negative, the electric field weakens or disappears, the conductive channel closes, and current stops flowing. This allows the MOSFET to act as a switch, opening or closing the current path by controlling the gate voltage.
2. Working principle of IRF740
A MOSFET is an electric field-controlled switching device that controls the flow of current from source to drain by applying an appropriate voltage (usually a positive voltage) to its gate. When the gate voltage is above the blocking voltage, the IRF740 will conduct, allowing current to flow through the device. When the gate voltage falls below the blocking voltage, the IRF740 turns off and current stops flowing.
1. Applications of IRF640
• UPS
• Quickly switch apps
• Battery Management System (BMS)
• Solar powered circuit
• Motor control driver applications
2. Applications of IRF740
• Motor driven
• Power management
• Electrical tools
• Electric vehicles and solar inverters
As shown in the picture, they are identical in pinout. The pin functions are as follows:
Pin 1（GATE）：The gate terminal will be used to trigger the MOSFET device.
Pin 2（DRAIN）：The drain is the input terminal of the MOSFET.
Pin 3（SOURCE）：In the source, terminal current flows out from the MOSFET.
• High temperature adaptability: Both IRF640 and IRF740 are able to work normally at high temperatures.
• High efficiency: Due to their low on-resistance and fast switching speed, these two transistors can achieve higher efficiency. For applications such as power supplies, this means less energy loss and higher power utilization.
• Low on-resistance: The IRF640 and IRF740 have a low on-resistance, which means they have lower resistance when in the on-state, thus reducing energy consumption.
• Fast switching: These two transistors switch very quickly, allowing for efficient switching operation and suitable for applications requiring fast response.
• Rugged: The transistors are designed to withstand high voltages and currents, providing stable performance in harsh operating environments.
• Packaging adaptability: Both IRF640 and IRF740 have a variety of packaging forms to choose from, adapting to the needs of different application scenarios. For example, the TO-220 package of IRF640 is generally suitable for industrial and commercial applications with a power consumption of about 50W, while the IRF740 has two packaging forms, TO-220 and SMD-220, to adapt to the needs of different application scenarios.
Frequently Asked Questions
1. What is the equivalent of IRF740?
You could use IRFB13N50A, UF450A, SSF13N15 as IRF740 Equivalent.
2. Is the IRF640 suitable for high-frequency applications?
No, the IRF640 is not designed for high-frequency applications due to its relatively high input capacitance. It is better suited for low to moderate frequency switching.
3. What is IRF740 Mosfet?
The IRF740 is an N-Channel Power MOSFET which can switch loads upto 400V. The Mosfet could switch loads that consume upto 10A, it can turned on by provide a gate threshold voltage of 10V across the Gate and Source pin.
4. What is the use of IRF740?
This device is mainly used for fast switching applications and comes with ultra-low on-resistance of 0.55 Ohms which is the resistance between drain and source terminals. The IRF740 contains three terminals named source, drain, and gate.
5. Are there any precautions to consider when using the IRF640?
Yes, it's crucial to operate the IRF640 within its specified voltage and current ratings to prevent overheating and potential damage. Proper heat sinking and driving circuitry should also be employed to ensure reliable performance.
