The Problem :

Accidentally connecting power supply wires in reverse can damage sensitive electronics. This common mistake can ruin circuits, especially for hobbyists and engineers prototyping new designs. Reverse voltage protection prevents this by blocking current flow in the wrong direction. One effective solution is using a PMOS MOSFET as a high-side switch.

The Solution :

A PMOS MOSFET is placed between the power supply and the load. When the voltage is correctly applied, the MOSFET turns on, allowing current to flow. If the polarity is reversed, the MOSFET stays off, blocking current and protecting the circuit.

Practical Example :

Consider powering an Arduino with a 12V battery. Without protection, reverse polarity can damage the board. Using a PMOS MOSFET with a low Rds(on) ensures that if the battery is connected incorrectly, the MOSFET blocks current, protecting your project.

Sample Calculation :

To select the right MOSFET:

• Assume load current is 2A, and acceptable voltage drop is 0.1V.

• Choose a MOSFET with Rds(on) < 0.05 ohms to minimize losses:

$$V=I\times R=2A\times 0.05\Omega =0.1V$$

Recommended Products :

For reliable protection, explore PMOS MOSFETs and diodes available at [SmartXProKits]. Shop now and protect your circuits!

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