What is power supply anti-reverse connection protection?

Power supply anti-reverse connection protection is a critical consideration in the design of any electronic device that relies on external power sources. By implementing the right protection mechanisms—whether through diodes, relays, MOSFETs, or specialized ICs—designers can ensure the long-term reliability and safety of their products.

What happens if a power supply is reversed?

A reverse connection can cause: Overheating: Components may overheat due to excessive current flow. Component Failure: Some components, like electrolytic capacitors and diodes, may fail instantly when exposed to reverse voltages. Power Supply Damage: The power supply itself might burn out or enter a failure mode if it lacks protection.

What makes a good reverse connection protection circuit?

A good reverse connection protection circuit, at the cost of adding a few more components, ensures the safety and responsibility towards the users/products. As shown in the diagram, a diode (unidirectional conductivity) is added in the positive/negative path of the power supply to achieve reverse connection protection.

What happens if you connect power supply terminals in reverse?

Whether it’s during the initial setup, or due to human error, connecting power supply terminals in reverse can lead to short circuits, component failure, and system malfunctions. An effective anti-reverse connection circuit design ensures that devices remain operational even when the input power is incorrectly connected.

Should a reverse based diode be added across a power supply?

When reading application notes, I've came with the suggestion of adding reverse-based diodes across each of power supplies connected in series. A diode in reverse bias must be added across output terminals of each power supply. This is to prevent -V voltage being applied to other power supply in fault conditions such as short circuit across load.

Can a MOS tube be used as a reverse connection protection circuit?

After the power supply is reversed, the MOS tube becomes an open circuit, effectively protecting the subsequent circuit. This method is widely used, and it is recommended to use N-MOS in practice. MOSFET has a lower on-resistance (\ (R_ {DS (on)}\)) and can be used as a reverse connection protection circuit with only a small power loss.