How to Use Pololu Big MOSFET Pushbutton Electronic Power Switch MP, 8A 4.5 to 40V: Examples, Pinouts, and Specs

The Pololu Big MOSFET Pushbutton Electronic Power Switch MP (Manufacturer Part ID: PololuBigMOSFET) is a high-power electronic switch designed for efficient and reliable control of electrical circuits. It utilizes a MOSFET to manage the flow of electricity, enabling easy on/off operation through a pushbutton interface. This switch is capable of handling currents up to 8A and operates within a wide voltage range of 4.5V to 40V, making it suitable for a variety of applications.

• Power control for high-current devices such as motors, LEDs, and heaters.
• Battery-powered systems requiring low standby current.
• Robotics and automation projects.
• DIY electronics and prototyping.
• Replacing mechanical switches for improved durability and reliability.

Below are the key technical details of the Pololu Big MOSFET Pushbutton Electronic Power Switch MP:

The Pololu Big MOSFET Pushbutton Switch has the following pinout:

1. Power Connections:

   • Connect the VIN pin to the positive terminal of your power source (e.g., battery or power supply).
   • Connect the GND pin to the negative terminal of your power source.
   • Connect the VOUT pin to the positive terminal of your load (e.g., motor, LED strip, etc.).
   • Ensure the load's current and voltage requirements are within the switch's specifications.

2. Pushbutton Operation:

   • Use a momentary pushbutton to toggle the switch on or off. The switch will remain in its current state until toggled again.

3. Optional Control Pins:

   • To turn the switch on programmatically, pull the ON pin high (e.g., using a microcontroller).
   • To turn the switch off programmatically, pull the OFF pin high.

4. Mounting:

   • The compact size of the switch allows for easy integration into your project. Use soldering or a breadboard for connections.

• Heat Dissipation: At high currents, the MOSFET may generate heat. Ensure adequate ventilation or use a heatsink if necessary.
• Voltage Spikes: For inductive loads (e.g., motors), use a flyback diode across the load to protect the switch from voltage spikes.
• Current Limits: Do not exceed the maximum continuous current rating of 8A to avoid damaging the switch.
• Standby Current: The switch consumes minimal standby current (< 0.01 mA), making it ideal for battery-powered applications.

The Pololu Big MOSFET Pushbutton Switch can be controlled using an Arduino UNO. Below is an example code to toggle the switch using the ON and OFF pins.

// Define the control pins connected to the Pololu switch
const int onPin = 7;  // Arduino pin connected to the ON pin of the switch
const int offPin = 8; // Arduino pin connected to the OFF pin of the switch

void setup() {
  // Set the control pins as outputs
  pinMode(onPin, OUTPUT);
  pinMode(offPin, OUTPUT);

  // Ensure the switch is off at startup
  digitalWrite(onPin, LOW);
  digitalWrite(offPin, LOW);
}

void loop() {
  // Turn the switch on
  digitalWrite(onPin, HIGH);
  delay(1000); // Keep the switch on for 1 second
  digitalWrite(onPin, LOW);

  // Turn the switch off
  digitalWrite(offPin, HIGH);
  delay(1000); // Keep the switch off for 1 second
  digitalWrite(offPin, LOW);
}

1. Switch Does Not Turn On:

   • Verify that the input voltage is within the specified range (4.5V to 40V).
   • Check the pushbutton or control pin connections for proper operation.
   • Ensure the load is connected correctly to the VOUT pin.

2. Switch Turns Off Unexpectedly:

   • Check if the load is drawing more than 8A, which may trigger thermal shutdown.
   • Inspect the power source for stability and ensure it can handle the load's current requirements.

3. Excessive Heat:

   • Ensure the switch is not operating near its maximum current limit for extended periods.
   • Add a heatsink or improve ventilation if necessary.

4. No Output Voltage:

   • Confirm that the switch is in the "on" state by checking the control pins or pushbutton.
   • Verify all connections, especially the VIN, VOUT, and GND pins.

Q: Can I use this switch with a 12V motor?
A: Yes, the switch supports a voltage range of 4.5V to 40V and can handle up to 8A, making it suitable for most 12V motors.

Q: Is the switch latching or momentary?
A: The switch is latching, meaning it stays in its current state (on or off) until toggled again.

Q: Can I control the switch with a microcontroller?
A: Yes, you can use the ON and OFF pins to control the switch programmatically with a microcontroller like an Arduino.

Q: Does the switch have reverse polarity protection?
A: No, the switch does not have built-in reverse polarity protection. Ensure correct polarity when connecting the power source.