Pololu Reverse Voltage Protector (4-60V 25A)

This Pololu module protects a connected load from reverse voltages down to -60V. This version does not block reverse current, making it suitable for applications such as battery-powered motor control where delivering energy back into the supply is desirable.

Pololu Reverse Voltage Protectors are compact modules that can be inserted between a power supply and its load to protect that load from damage in the case of accidental reversal of power polarity. They operate from 4V (3.2V after startup) to 60V and provide protection from negative voltages down to -60V.

We also stock a version with reverse current blocking.

Note: Any voltage on the output will reduce the 60V maximum rating. For example, if there is a large capacitor charged to 24V on the output, the minimum negative voltage would be -36V.

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This specific module uses an LM74500-Q1 reverse voltage protection controller and N-channel MOSFET to provide protection from negative voltages down to -60V. It operates from 4V (3.2V after startup) to 60V and has a VIN path impedance of approximately 1.5mΩ when the MOSFET is on (i.e. when power is connected with the proper polarity), enabling currents up to around 25A continuous (and up to around 50A for a few seconds).

This version does not block reverse current, making it suitable for applications such as battery-powered motor control where delivering energy back into the supply is desirable.

Operating voltage	Max current	MOSFET on resistance	Reverse current blocking
4 V – 60 V*	25 A	< 1.5 mΩ	No

Connections

Supply power and ground connect to the VIN and GND side of the board, and the VOUT and GND pins connect to the load. If the supply is connected correctly, with its positive voltage on VIN, the power will pass through the board to VOUT. If the supply is connected incorrectly, with the positive voltage on GND, supply power will not pass through to the output, and any connected load will be protected from the reversed supply voltage.

The larger input and output through-holes can accommodate 5mm-pitch terminal blocks or up to 14 AWG wires, and the smaller through-holes are spaced for 0.1″-pitch headers.

Optional TVS diode mounting location

There are pads for adding an optional SMB-size transient voltage suppressor (TVS) across VIN and GND on the bottom side of the board:

Specifications

Minimum operating voltage	4V
Maximum operating voltage	60V
Maximum current	25A
Reverse current blocking	N
Size	0.435″ × 0.7″ × 0.11″
Weight	0.7g

Resources

• Dimensions
• 3D Model (STEP)
• Drill guide
• TI LM74500-Q1 datasheet
• TI LM74700-Q1 datasheet
• Schematic