How to Use FR120N mosfet board: Examples, Pinouts, and Specs

The FR120N MOSFET board is a compact circuit board that integrates the FR120N MOSFET, a high-performance N-channel power MOSFET. This component is widely used in power management applications due to its high efficiency, low on-resistance, and fast switching capabilities. The board simplifies the use of the FR120N MOSFET by providing easy-to-access pins and a pre-soldered configuration, making it ideal for prototyping and integration into various electronic projects.

• DC motor control
• LED dimming and lighting control
• Power supply regulation
• Battery management systems
• High-speed switching circuits
• Arduino and microcontroller-based projects

• MOSFET Type: N-channel
• Maximum Drain-Source Voltage (V_DS): 100V
• Maximum Continuous Drain Current (I_D): 9.7A
• Gate Threshold Voltage (V_GS(th)): 2.0V - 4.0V
• Maximum Power Dissipation (P_D): 45W
• On-Resistance (R_DS(on)): 0.12Ω (typical)
• Switching Speed: Fast (rise time ~ 10ns, fall time ~ 30ns)
• Operating Temperature Range: -55°C to +175°C

The FR120N MOSFET board typically has three main pins for interfacing with external circuits. These pins are labeled as follows:

1. Power Supply: Ensure the power supply voltage does not exceed the maximum V_DS rating of 100V.
2. Gate Control: Connect the Gate pin to a microcontroller or driver circuit capable of providing a voltage between 2V and 10V to fully turn on the MOSFET.
3. Load Connection: Connect the load (e.g., motor, LED, etc.) between the Drain pin and the positive terminal of the power supply.
4. Source Connection: Connect the Source pin to the ground of the circuit.
5. Gate Resistor (Optional): Use a resistor (e.g., 220Ω) between the microcontroller and the Gate pin to limit inrush current and protect the microcontroller.
6. Flyback Diode (For Inductive Loads): When driving inductive loads like motors or relays, connect a flyback diode across the load to protect the MOSFET from voltage spikes.

• Heat Dissipation: Use a heatsink or active cooling if the MOSFET operates near its maximum current or power dissipation limits.
• Gate Voltage: Ensure the Gate voltage is within the recommended range to avoid damage or improper operation.
• Switching Speed: Minimize the length of the Gate connection to reduce noise and improve switching performance.
• Arduino Compatibility: The FR120N MOSFET can be directly controlled by an Arduino, but ensure the Gate voltage is sufficient to fully turn on the MOSFET.

Below is an example of how to use the FR120N MOSFET board to control an LED with an Arduino UNO:

// Define the pin connected to the MOSFET Gate
const int mosfetGatePin = 9;

void setup() {
  // Set the MOSFET Gate pin as an output
  pinMode(mosfetGatePin, OUTPUT);
}

void loop() {
  // Turn the MOSFET on (LED ON)
  digitalWrite(mosfetGatePin, HIGH);
  delay(1000); // Keep the LED on for 1 second

  // Turn the MOSFET off (LED OFF)
  digitalWrite(mosfetGatePin, LOW);
  delay(1000); // Keep the LED off for 1 second
}

Note: Use a current-limiting resistor with the LED to prevent damage.

1. MOSFET Not Switching Properly

   • Cause: Insufficient Gate voltage.
   • Solution: Ensure the Gate voltage is at least 5V for full switching. Use a Gate driver if necessary.

2. Overheating

   • Cause: Excessive current or inadequate cooling.
   • Solution: Add a heatsink or active cooling. Ensure the current is within the MOSFET's rated limits.

3. Load Not Operating

   • Cause: Incorrect wiring or damaged MOSFET.
   • Solution: Double-check the wiring. Test the MOSFET with a multimeter to verify functionality.

4. Voltage Spikes Damaging the MOSFET

   • Cause: Inductive load without a flyback diode.
   • Solution: Add a flyback diode across the load to suppress voltage spikes.

• Can the FR120N MOSFET board handle AC loads?

  • No, the FR120N is designed for DC applications only.

• What is the maximum PWM frequency for this MOSFET?

  • The FR120N can handle PWM frequencies up to several kHz, depending on the Gate drive strength and circuit design.

• Do I need a Gate driver for this MOSFET?

  • For low-power applications, a microcontroller can directly drive the Gate. For high-power or high-speed switching, a dedicated Gate driver is recommended.

• Can I use this MOSFET with a 3.3V microcontroller?

  • The FR120N requires a Gate voltage of at least 2V to start switching, but 3.3V may not fully turn it on. Use a logic-level MOSFET or a Gate driver for 3.3V systems.