Pololu Reverse Voltage Protector, 4-60V, 25A

Overview

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 4 V (3.2 V after startup) to 60 V and provide protection from negative voltages down to -60 V. They are available in different power levels and with or without reverse current blocking:

Reverse protection	Max current	MOSFET on resistance	Size	Price	Pololu Item #
Reverse voltage only	10 A	< 10 mΩ	0.3″×0.5″	$1.49	#5380
	12 A	< 5 mΩ		$1.95	#5381
	25 A	< 1.5 mΩ	0.435″×0.7″	$3.59	#5387
Reverse voltage and current (ideal diode)	10 A	< 10 mΩ	0.3″×0.5″	$1.75	#5382
	12 A	< 5 mΩ		$2.25	#5383
	25 A	< 1.5 mΩ	0.435″×0.7″	$3.95	#5389

The versions without reverse current blocking are suitable for applications such as battery-powered motor control where the ability to deliver energy back into the supply is desirable. The versions with reverse current blocking act as ideal diodes, preventing any current from flowing from the load back into the supply.

Size comparison of the 25A (top) and 10A/12A (bottom) Pololu Reverse Voltage Protectors.

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

Details for item #5387

Pololu Reverse Voltage Protector, 4-60V, 25A, top view.

Pololu 25A Reverse Voltage Protector/Ideal Diode Reverse Voltage Protector, bottom view.

This module uses an LM74500-Q1 reverse voltage protection controller and N-channel MOSFET to provide protection from negative voltages down to -60 V. It operates from 4 V (3.2V after startup) to 60 V and has a VIN path impedance of approximately 1.5 mΩ when the MOSFET is on (i.e. when power is connected with the proper polarity), enabling currents up to around 25 A continuous (and up to around 50 A 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	Size
4 V – 60 V*	25 A	< 1.5 mΩ	no	0.435″×0.7″
* Operates down to 3.2 V after startup.

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.

Pololu 25A Reverse Voltage Protector with a pair of two-pin, 5mm-pitch screw terminal blocks (not included).

Pololu 25A Reverse Voltage Protector with a pair of two-pin, 5mm-pitch screw terminal blocks (not included).

Pololu 25A Reverse Voltage Protector soldered with 14 AWG wires.

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:

We can manufacture these with the TVS diode of your choice for custom high-volume orders (typically at least a few hundred pieces). If you are interested in such a customization, please contact us for a quote.

Schematic