We’re happy to announce our new Isolated Solid State Relay/Switch boards! These modules function as solid state, single-pole, single-throw (SPST) relays or switches that can be controlled by low-current signals between 2.7 V and 40 V. The control signal activates an optically coupled driver that turns on a pair of output MOSFETs, which keeps the outputs electrically isolated from the input side. The MOSFETs are arranged back-to-back to make the outputs symmetric and bidirectional (so the board can be used as a high-side or low-side switch).

These boards make good replacements for mechanical relays in many situations, since their semiconductor-based design allows them to avoid problems like contact wear and arcing that limit the service life of mechanical relays. They are also silent and generally much smaller than a typical mechanical relay with a comparable current rating. Two versions of the solid state relay/switch are available with different voltage and current capabilities:

• Pololu Isolated Solid State Relay/Switch, SPST, 30V, 11A
• Pololu Isolated Solid State Relay/Switch, SPST, 60V, 7A

Three-wire and two-wire (with EN and VIN tied together) control options for the Pololu Isolated Solid State Relay/Switch, SPST.

Introductory special discount! Use coupon code SSRELAYINTRO to get either version for $3.50 each.

Related products

	Pololu Isolated Solid State Relay/Switch, SPST, 30V, 11A
	Pololu Isolated Solid State Relay/Switch, SPST, 60V, 7A

ACS3704x Current Sensor Micro Carrier (top) and Compact Carrier (bottom) basic dimensions with US quarter for size reference.

ACS37030 Current Sensor Compact Carrier (top) and Large Carrier (bottom) size comparison.

We have released even more current sensors! As with our assortment of other active and preferred current sensors, these new boards are based on Allegro current-sensing ICs and have analog outputs with voltage proportional to the AC or DC current passing through the sensor while offering full electrical isolation of the current path from the sensor’s electronics. This isolation allows them to be inserted anywhere in the current path, including on the high side, and because the current path resistance is on the order of 2 mΩ or less, there is minimal effect on the rest of the system. Here’s a quick summary of the new sensor families:

Allegro ACS37041/ACS37042

These low-cost bidirectional current sensors have ranges of -10 A to +10 A or -30 A to +30 A with dedicated versions for 3.3 V and 5 V systems. The sensor itself is a tiny 5-pin SOT-23 package, which allows for an extra-compact, “micro” carrier board that is approximately 1/5th the size of our next smallest current sensor carrier. We also have versions in our standard “compact” form factor, which for these sensors end up being the larger of the two form factors available. These larger versions can accommodate a wider variety of connectors and thicker wires, and they have the same overall dimensions and current-path mounting hole arrangements as our other “compact” current sensor carriers.

The ACS37041 and ACS37042 are almost identical, with the key difference being that the ACS37042 has a higher isolation voltage rating. To support operation at higher voltages, the carrier boards for the ACS37042 versions have routed slots for higher creepage distances along the PCB surface. The pictures above show the ACS37041 carriers on the left and the ACS37042 carriers on the right.

The following table shows all of our ACS37041 and ACS37042 carrier options:

	Pololu Item #	Part Suffix	Isolation Rating 1	Supply Voltage	Current Range	Sensitivity (mV/A)	Zero Point	Size	PCB Details	Min PCB Creepage 2	Price
ACS3704x Micro Carriers
ACS37041	#5440 (coming June 2025)	010B3	100 VRMS	3.0 V to 3.6 V	±10 A	132	1.65 V	0.3″×0.4″ 7.6×10.2 mm	2 layers, 1-oz copper	1.6 mm	$3.65
	#5441	030B3			±30 A	44
	#5442	010B5		4.5 V to 5.5 V	±10 A	200	2.5 V
	#5443	030B5			±30 A	66.7
ACS37042	#5450	010B3	285 VRMS	3.0 V to 3.6 V	±10 A	132	1.65 V			2.0 mm	$4.19
	#5451	030B3			±30 A	44
	#5452 (coming June 2025)	010B5		4.5 V to 5.5 V	±10 A	200	2.5 V
	#5453 (coming June 2025)	030B5			±30 A	66.7
ACS3704x Compact Carriers
ACS37041	#5444 (coming June 2025)	010B3	100 VRMS	3.0 V to 3.6 V	±10 A	132	1.65 V	0.7″×0.8″ 17.8×20.3 mm	2 layers, 2-oz copper	1.6 mm	$3.95
	#5445	030B3			±30 A	44
	#5446	010B5		4.5 V to 5.5 V	±10 A	200	2.5 V
	#5447	030B5			±30 A	66.7
ACS37042	#5454	010B3	285 VRMS	3.0 V to 3.6 V	±10 A	132	1.65 V			3.0 mm	$4.49
	#5455	030B3			±30 A	44
	#5456 (coming June 2025)	010B5		4.5 V to 5.5 V	±10 A	200	2.5 V
	#5457 (coming June 2025)	030B5			±30 A	66.7
Note 1: IC component rating per manufacturer datasheet.
Note 2: Minimum creepage along PCB surface based on layout design only. Other creepage distances, e.g. along the body of the component, may be lower.

Allegro ACS37030

These sensors measure bidirectional currents from -20 A to +20 A or -65 A to +65 A, and they are intended for 3.3 V systems. What makes them really special are their extra-low (40 ns typical) response times and extra-high 5 MHz bandwidth, which are made possible by their combined use of two sensing technologies: a Hall effect sensor captures DC and low-frequency current information and an inductive coil captures high-frequency signals. The following table shows our available options:

	Pololu Item #	Part Suffix	Supply Voltage	Current Range	Sensitivity (mV/A)	Zero Point	Size	PCB Details	Price
ACS37030 Compact Carriers
	#5230	020B3	3.0 V to 3.6 V	±20 A	66	1.65 V	0.7″×0.8″ 17.8×20.3 mm	2 layers, 2-oz copper	$9.95
	#5231 (coming July 2025)	040B3		±40 A	33
	#5232	065B3		±65 A	20.3
ACS37030 Large Carriers
	#5235	065B3	3.0 V to 3.6 V	±65 A	20.3	1.65 V	1.4″×1.2″ 35.6×30.5 mm	6 layers, 2-oz copper	$12.95
	#5236 (coming July 2025)	040B3		±40 A	33

These sensors are available in our standard compact form factor, which is great for use in space-constrained systems, and the higher-current versions are also available in our standard large form factor, which supports support more connection options for higher-current applications. The large carriers offer better thermal dissipation thanks to their 6-layer PCBs and increased surface area, and the holes and slots for the current path connection points accommodate thicker wires along with a variety of high-current connectors (e.g. lugs, solderless ring terminals, and 4-pin terminal blocks). Having these standard form factors available makes it easier to swap among different boards to compare different sensor ICs, and having different form factors available for the same sensor IC also makes it possible to evaluate how things like PCB area and the number of copper layers affects the sensor’s thermal performance

All our current sensors

These new additions bring us up to 96 total active and preferred current sensor carriers! Here’s a handy table comparing them all:

	ACS3704x Current Sensor Micro Carriers	ACS3704x Current Sensor Compact Carriers	ACS711 Current Sensor Carriers	ACS71240 Current Sensor Carriers	ACS724 Current Sensor Carriers	ACS37220 Current Sensor Compact Carriers	ACS37220 Current Sensor Large Carriers	ACS37030 Current Sensor Compact Carriers	ACS37030 Current Sensor Large Carriers	ACS72981 Current Sensor Compact Carriers	ACS72981 Current Sensor Large Carriers	CT432/CT433 TMR Current Sensor Compact Carriers	CT432/CT433 TMR Current Sensor Large Carriers
Allegro Sensor	ACS3704x		ACS711KEXT	ACS71240	ACS724LLCTR	ACS37220		ACS37030		ACS72981xLR		CT432/CT433
Sensing technology	Hall effect		Hall effect	Hall effect	Hall effect	Hall effect		Hall effect + inductive coil		Hall effect		XtremeSense™ TMR (tunneling magnetoresistance)
Logic voltage range	3.3V versions: 3.0–3.6 V 5V versions: 4.75–5.5 V		3.0–5.5 V	3.3V ver: 3.0–3.6 V 5V ver: 4.5–5.5 V	4.5–5.5 V	3.3V versions: 3.15–3.45 V 5V versions: 4.5–5.5 V		3.0–3.6 V		3.3V versions: 3.0–3.6 V 5V versions: 4.5–5.5 V		3.3V versions: 3.0–3.6 V 5V versions: 4.75–5.5 V
Family current range	10–30 A		15.5–31 A	10–50 A	2.5–50 A	100–200 A		20–65 A		50–200 A		20–70 A
Current range/ sensitivity of individual versions	ACS37041: 3.3V Bidirectional: ±30 A / 44 mV/A 5V Bidirectional: ±10 A / 200 mV/A ±30 A / 66.7 mV/A ACS37042: 3.3V Bidirectional: ±10 A / 132 mV/A ±30 A / 44 mV/A	ACS37041: 3.3V Bidirectional: ±30 A / 44 mV/A 5V Bidirectional: ±10 A / 200 mV/A ±30 A / 66.7 mV/A ACS37042: 3.3V Bidirectional: ±10 A / 132 mV/A ±30 A / 44 mV/A	Bidirectional:(1) ±15.5 A / 90 mV/A ±31 A / 45 mV/A	3.3V Bidirectional: ±10 A / 132 mV/A ±30 A / 44 mV/A ±50 A / 26.4 mV/A 5V Bidirectional: ±10 A / 200 mV/A ±30 A / 66 mV/A ±50 A / 40 mV/A 5V Unidirectional: 0–⁠50 A / 80 mv/A	5V Bidirectional:(2) ±2.5 A / 800 mV/A ±5 A / 400 mV/A ±10 A / 200 mV/A ±20 A / 100 mV/A ±30 A / 66 mV/A ±50 A / 40 mV/A 5V Unidirectional:(2) 0–⁠5 A / 800 mv/A 0–⁠10 A / 400 mv/A 0–⁠20 A / 200 mv/A 0–⁠30 A / 133 mV/A	3.3V Bidirectional: ±100 A / 13.2 mV/A ±150 A / 8.8 mV/A 5V Bidirectional: ±100 A / 20 mV/A ±150 A / 13.3 mV/A ±200 A / 10 mV/A	3.3V Bidirectional: ±100 A / 13.2 mV/A ±150 A / 8.8 mV/A 5V Bidirectional: ±100 A / 20 mV/A ±150 A / 13.3 mV/A ±200 A / 10 mV/A	3.3V Bidirectional: ±20 A / 66 mV/A ±65 A / 20.3 mV/A	3.3V Bidirectional: ±65 A / 20.3 mV/A	3.3V Bidirectional:(1) ±50 A / 26.4 mV/A ±100 A / 13.2 mV/A ±150 A / 8.8 mV/A ±200 A / 6.6 mV/A 3.3V Unidirectional:(1) 0–⁠50 A / 52.8 mv/A 0–⁠100 A / 26.4 mv/A 0–⁠150 A / 17.6 mv/A 0–⁠200 A / 13.2 mv/A 5V Bidirectional:(2) ±50 A / 40 mV/A ±100 A / 20 mV/A ±150 A / 13.3 mV/A ±200 A / 10 mV/A 5V Unidirectional:(2) 0–⁠50 A / 80 mv/A 0–⁠100 A / 40 mv/A 0–⁠150 A / 26.7 mv/A	3.3V Bidirectional:(1) ±50 A / 26.4 mV/A ±100 A / 13.2 mV/A ±150 A / 8.8 mV/A ±200 A / 6.6 mV/A 3.3V Unidirectional:(1) 0–⁠50 A / 52.8 mv/A 0–⁠100 A / 26.4 mv/A 0–⁠150 A / 17.6 mv/A 0–⁠200 A / 13.2 mv/A 5V Bidirectional:(2) ±50 A / 40 mV/A ±100 A / 20 mV/A ±150 A / 13.3 mV/A ±200 A / 10 mV/A 5V Unidirectional:(2) 0–⁠50 A / 80 mv/A 0–⁠100 A / 40 mv/A 0–⁠150 A / 26.7 mv/A	3.3V Bidirectional: ±20 A / 50 mV/A ±30 A / 33.3 mV/A ±50 A / 20 mV/A ±70 A / 14.3 mV/A 3.3V Unidirectional: 0–⁠20 A / 100 mv/A 0–⁠30 A / 66.7 mv/A 0–⁠50 A / 40 mv/A 0–⁠65 A / 30.8 mv/A 5V Bidirectional: ±20 A / 100 mV/A ±30 A / 66.7 mV/A ±50 A / 40 mV/A ±65 A / 30.8 mV/A 5V Unidirectional: 0–⁠20 A / 200 mv/A 0–⁠30 A / 133.3 mv/A 0–⁠50 A / 80 mv/A 0–⁠70 A / 57.1 mv/A	3.3V Bidirectional: ±50 A / 20 mV/A ±70 A / 14.3 mV/A 3.3V Unidirectional: 0–⁠50 A / 40 mv/A 0–⁠65 A / 30.8 mv/A 5V Bidirectional: ±50 A / 40 mV/A ±65 A / 30.8 mV/A 5V Unidirectional: 0–⁠50 A / 80 mv/A 0–⁠70 A / 57.1 mv/A
IC current path resistance	1.6 mΩ		0.6 mΩ	0.6 mΩ	0.6 mΩ	0.1 mΩ		0.7 mΩ		0.2 mΩ		1 mΩ
PCB	2 layers, 1-oz copper	2 layers, 2-oz copper	2 layers, 2-oz copper	2 layers, 2-oz copper	2 layers, 2- or 4-oz copper(4)	2 layers, 2-oz copper	6 layers, 2-oz copper	2 layers, 2-oz copper	6 layers, 2-oz copper	6 layers, 2-oz copper	6 layers, 2-oz copper	2 or 4 layers(5), 2-oz copper	6 layers, 2-oz copper
Max bandwidth	150 kHz		100 kHz	120 kHz	120 kHz(3)	150 kHz		5 MHz		250 kHz		1 MHz
Size	0.3″ × 0.4″	0.7″ × 0.8″	0.7″ × 0.8″	0.7″ × 0.8″	0.7″ × 0.8″	0.7″ × 0.8″	1.4″ × 1.2″	0.7″ × 0.8″	1.4″ × 1.2″	0.7″ × 0.8″	1.4″ × 1.2″	0.8″ × 1.1″	1.4″ × 1.2″
Overcurrent fault output						User-configurable threshold
Common-mode field rejection
Nonratiometric output
1-piece price	$3.65	$3.95	$4.35	$4.75	$8.95 – $10.49	$5.95	$8.95	$9.95	$12.95	$11.95	$14.95	$10.95	$14.95

Note 1: Sensitivity when Vcc = 3.3 V; actual sensitivity is ratiometric (i.e. it is proportional to Vcc).
Note 2: Sensitivity when Vcc = 5 V; actual sensitivity is ratiometric (i.e. it is proportional to Vcc).
Note 3: Bandwidth can be reduced by adding a filter capacitor.
Note 4: 50A version uses 4-oz copper PCB; all other versions use 2-oz copper.
Note 5: 50A and higher versions use a 4-layer PCB; all other versions use a 2-layer PCB.

You can also use the following selection box to see all these options sorted by current range:

Alternatives available with variations in these parameter(s): current range Select variant…

Related products

	ACS37042KLHBLT-030B3 Current Sensor Compact Carrier -30A to +30A, 3.3V
	ACS37030LLZATR-065B3 Current Sensor Compact Carrier -65A to +65A, 3.3V
	ACS37030LLZATR-065B3 Current Sensor Large Carrier -65A to +65A, 3.3V
	ACS37041KLHBLT-030B3 Current Sensor Micro Carrier -30A to +30A, 3.3V
	ACS37041KLHBLT-010B5 Current Sensor Micro Carrier -10A to +10A, 5V
	ACS37041KLHBLT-030B5 Current Sensor Micro Carrier -30A to +30A, 5V
	ACS37041KLHBLT-030B3 Current Sensor Compact Carrier -30A to +30A, 3.3V
	ACS37041KLHBLT-010B5 Current Sensor Compact Carrier -10A to +10A, 5V
	ACS37041KLHBLT-030B5 Current Sensor Compact Carrier -30A to +30A, 5V
	ACS37042KLHBLT-010B3 Current Sensor Micro Carrier -10A to +10A, 3.3V
	ACS37042KLHBLT-030B3 Current Sensor Micro Carrier -30A to +30A, 3.3V
	ACS37042KLHBLT-010B3 Current Sensor Compact Carrier -10A to +10A, 3.3V
	ACS37030LLZATR-020B3 Current Sensor Compact Carrier -20A to +20A, 3.3V

We’re excited to introduce our new isolated USB-to-I²C adapters! These boards make it easy to control your I²C device from your PC or other USB host, giving your applications access to a world of sensors and actuators or simplifying evaluation and troubleshooting of I²C hardware. Two versions are available, one that requires VCC to be supplied separately to the I²C side and one that can deliver 5V or 3.3V power to your I²C bus from your USB port while still maintaining electrical isolation.

Pololu Isolated USB-to-I²C Adapter pinout and LEDs.

Pololu Isolated USB-to-I²C Adapter with Isolated Power pinout and LEDs.

Both adapters offer full galvanic isolation to protect your PC from your experimental circuits and to avoid subtle common-ground problems.

Schematic diagram of the Pololu Isolated USB-to-I²C Adapter with Isolated Power.

The firmware is open source, so you can customize them, and the galvanic isolation building blocks used in these adapters are available separately in smaller modules if you want to implement your own isolated systems.

Related products

	Pololu Isolated USB-to-I²C Adapter
	Pololu Isolated USB-to-I²C Adapter with Isolated Power

We usually think of ground as a common point in our circuits, and many problems arise from not having a good (or any) ground connection. But there’s also the flip side of unexpected ground connections leading to malfunction or even destruction of our electronics systems. Keeping grounds separated can be an important part of improving functionality and reliability when connecting many parts or boards together, which is why we have continued our push into simplifying electrical isolation with the release of four new I²C isolator boards:

• Pololu I²C Isolator, ISO1640
• Pololu I²C Isolator with Connectors, ISO1640
• Pololu I²C Isolator with Isolated Power, ISO1640, MIE1W0505BGLVH, 5V/3.3V, 200mA
• Pololu I²C Isolator with Isolated Power and Connectors, ISO1640, MIE1W0505BGLVH, 5V/3.3V, 200mA

These modules enable bidirectional I²C communication between devices while maintaining complete galvanic isolation between the two sides. This prevents the unexpected flow of current between the two sides, and it can also prevent destructive voltages on one side from propagating into the other (note that in this scenario one side will still be destroyed, but at least the damage will be contained to the isolated portion). The modules are based on Texas Instruments’ ISO1640B, which supports bidirectional data transfer up to 1.7 MHz. The clock line (SCL) is also bidirectional, which allows for clock stretching.

Two board versions are available, one with isolated power and one without. The version with isolated power can deliver regulated, isolated power at 3.3 V or 5 V to the target thanks to the incorporation of the MPS MIE1W0505BGLVH (which you might recognize from the standalone power module we released a few months ago), while the simpler version without isolated power requires the two sides to be powered separately.

Schematic diagram of the Pololu I²C Isolator with Isolated Power.

Each version is optionally available with JST SH-style 4-pin connectors that are compatible with Qwiic and Stemma QT.

Introductory special discounts! Use coupon code I2CISOINTRO to get the versions without isolated power for $3.49 and use coupon code P5392P5393INTRO to get the versions with isolated power for $6.49.

Related products

	Pololu I²C Isolator with Isolated Power and Connectors, ISO1640, MIE1W0505BGLVH, 5V/3.3V, 200mA
	Pololu I²C Isolator with Isolated Power, ISO1640, MIE1W0505BGLVH, 5V/3.3V, 200mA
	Pololu I²C Isolator with Connectors, ISO1640
	Pololu I²C Isolator, ISO1640

We are excited to announce the release of two new higher-power reverse voltage protectors that can handle up to around 25 A continuous while protecting your 4V–60V circuit from accidental destruction from reverse voltage:

• Reverse protection only – This version protects against reverse voltage while still allowing reverse current, making it suitable for applications such as battery-powered motor control where delivering energy back into the battery is desirable.
• Reverse protection with reverse current blocking – This version acts as an ideal diode, preventing current from flowing from output to input.

These boards feature larger 5×6mm MOSFETs with lower on-resistances and more than double the current carrying ability of the versions we released a few months ago, which makes the overall module larger (but still compact!):

Pololu Reverse Voltage Protectors are available in 20A/25A (left) and 10A/12A (right) versions.

With these new releases, we now have six total reverse protector options (with or without reverse current blocking in three different power levels):

Introductory special discount! Use coupon code RVP25INTRO to get these new reverse voltage protectors for just $2.95!

Related products

	Pololu Reverse Voltage Protector, 4-60V, 25A
	Pololu Ideal Diode Reverse Voltage Protector, 4-60V, 25A
	Pololu Reverse Voltage Protector, 4-60V, 12A
	Pololu Ideal Diode Reverse Voltage Protector, 4-60V, 12A
	Pololu Reverse Voltage Protector, 4-60V, 10A
	Pololu Ideal Diode Reverse Voltage Protector, 4-60V, 10A

I am happy to introduce our first isolated power module, which we expect to kick off a new category of electrical isolation products (note that the many current sensors we carry also feature isolation from the sense side to the control side, but that isolation is part of their more dedicated current-sensing functionality). Many of our products are modules like motor controllers and regulator boards, and connecting several of them together in real-world settings can lead to unexpected problems from connecting all the grounds together. For example, your computer’s USB port can be a convenient source of 5 V, but the negative or ground side of that 5 V will likely be connected to the ground pin of the computer’s power cable and therefore to the ground side of everything else you have plugged into the wall. This can lead to unexpected problems as you build up your system, usually without thinking about your house being part of your circuit.

There are more and more solutions for effectively moving power and signals without having an electrical connection, so we will be working on adding those into our more integrated products, and we will be adding to our isolation module portfolio to support our customers with the building blocks to make safer and more reliable systems themselves.

The module we are introducing today can provide galvanically isolated and regulated 5 V or 3.3 V power at up to 200 mA. It’s based on the MIE1W0505BGLVH from MPS, and it’s amazing how much is integrated into a chip like that, including a transformer to get the power from one side to the other without an electrical connection. Only a few passives are needed to support the IC, allowing our board to be small (0.3″ × 0.6″) and low-cost. It’s easy to use, too, with all the necessary information provided on the product page. The datasheet is available if you want more information, but you can use this module without knowing the details in there. (This is unlike what we call “carrier boards”, which require you to familiarize yourself with the chip.)

Introductory special discount! Use coupon code 5384INTRO to get this new power module for just $2.75!

We’re excited to announce the release of our new High-Power Stepper Motor Driver 36v8 for controlling large bipolar stepper motors. It operates over a wide 8 V to 50 V range and can deliver up to 8 A continuous per phase (11 A peak with sufficient additional cooling), making it our most powerful stepper motor driver by far. Here are some of its key features:

• Highly configurable through SPI interface
• Optional STEP/DIR control pins (stepping can also be controlled through SPI interface alone)
• Nine different step resolutions down to 256 microsteps: full-step, half-step, 1/4-step, 1/8-step, 1/16-step, 1/32-step, 1/64-step, 1/128-step, and 1/256-step
• Adjustable current control lets you set the maximum current output, enabling the use of voltages above your stepper motor’s rated voltage to achieve higher step rates
• Adaptive blanking time, adjustable decay times, and various current decay modes enable the creation of ultra-smooth motion profiles through the SPI interface
• Optional STALL output enables stall detection when microstepping
• Optional BEMF output enables more advanced control and stall detection algorithms based on the back EMF of the stepper motor
• Driver supports alternate operating mode for controlling two brushed DC motors with PWM inputs instead of one bipolar stepper motor with STEP/DIR inputs
• Inputs compatible with 1.8 V, 3.3 V, and 5 V logic
• Digital outputs are all open drain with pull-ups to externally supplied IOREF voltage for use with non-5V systems (IOREF can be connected to neighboring 5V OUT pin for use with 5V systems)
• Under-voltage lockout, over-current protection, short circuit protection, and reverse-voltage protection
• Arduino library and example sketches are available that provide basic functions for configuring and operating the driver

The 36v8 board has the same dimensions and pinout as the our older 36v4 version, so you can easily swap in this newer version to double the power to existing projects (or get the same power at lower temperatures).

Introductory special discount! Be one of the first to try out these new drivers and save $5 with coupon code HPSMD36V8INTRO!

Related products

	Pololu High-Power Stepper Motor Driver 36v8
	Pololu High-Power Stepper Motor Driver 36v4

We just released several small reverse voltage protection and ideal diode boards that can protect your projects from reverse voltage application. We have reverse-voltage protection built into many of our products, and we usually implement it using a P-channel MOSFET, like this:

Reverse-voltage protection using a P-channel MOSFET.

This approach is usually more efficient than just using a diode since the MOSFET has a lower voltage drop across it. However, P-channel MOSFETs have worse on-resistances than N-channel MOSFETs of similar prices and sizes. This has not mattered much for our lower-powered products, but that limitation is becoming more apparent as we are developing more products with maximum operating voltages over 40 V. The next common MOSFET voltage above 40 V is 60 V, and at that voltage and with currents above around 10 A, it starts becoming more size-efficient to use an N-channel MOSFET plus an extra chip to manage the additional complexities of controlling the N-channel MOSFET in this kind of application. This is how that circuit looks:

Schematic diagram of the Pololu Reverse Voltage Protectors.

Since we are planning on using this approach on several new products, we decided to make standalone product versions as well. Here are how the first products look, using 3×3 mm MOSFETs:

This lets us get up to about 10-12 amps continuous current and an operating range of 4-60 V, which is perfect for most of our products. We tried to make the board as small as possible, and for the input and output connections we are using a new slot approach that lets the boards work with standard 0.1" headers or connectors, 3.5 mm connectors, and 5 mm connectors.

Examples of various connectors that can be used with the Pololu 10A/12A Reverse Voltage Protectors (from left to right: 5mm terminal blocks, 3.5mm terminal blocks, 0.1″ headers).

Texas Instruments offers two similar parts for the MOSFET controller. The LM74500 offers the same functionality as the simple P-channel MOSFET, allowing current to flow in both directions as long as the polarity is correct. This is useful for applications such as motor drivers where we want power to be able to flow back from the motor into the battery. There is also the LM74700 version, which makes the circuit function as an ideal diode, allowing current to flow in only one direction. We are offering our boards with both controller options and with two MOSFET options, for a total of four product versions:

The datasheets for the LM74500-Q1 reverse voltage protection controller and LM74700-Q1 reverse voltage protection ideal diode controller provide additional information about adding a transient voltage suppressor (TVS) diode across the input as part of a more general input protection circuit. We have pads for an SMB-size TVS on the back side of the board for those interested in adding this kind of protection:

As with our other electronics products, we make these at our Las Vegas, Nevada headquarters, so we can build custom versions with that TVS populated with a part of your choice (typical minimum quantities to make that worthwhile are around 200 pieces).

Are these interesting products? Would you want to see higher-current versions with bigger MOSFETs? Let us know in the comments or on our X and Facebook posts.

Introductory special discount! Try some out for as low as $1.16 each using our introductory special coupon, RVPINTRO (limit 5 per version)!

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	Pololu Ideal Diode Reverse Voltage Protector, 4-60V, 10A
	Pololu Reverse Voltage Protector, 4-60V, 12A
	Pololu Reverse Voltage Protector, 4-60V, 10A

We just released the new D45V1ExFx line of small voltage regulators that can efficiently deliver up to 100 mA from input voltages up to 65 V. The small size, high efficiency, and wide input voltage range make these especially worth considering for low-power projects involving wildly fluctuating sources such as solar panels (you can see from my post yesterday that I have had solar on my mind lately) and other energy harvesting technologies. You might also just want the peace of mind of having the extra input voltage margin on something like a 24 V project that might have occasional spikes from something electrically noisy also being supplied by the same line. Or you might just have a few of these around for their small size and high efficiency at low currents.

Typical efficiency of the Step-Down Voltage Regulator D45V1ExF5.

(The 70-90% efficiency by itself is not particularly notable, but that efficiency is maintained to output currents of a few mA, which is kind of special.)

We are offering basically the same regulator circuit in two form factors. The D45V1E1Fx family has components on both sides of the PCB and measures just 0.3″ × 0.5″, making them our smallest step-down regulators.

D45V1E1Fx step-down voltage regulator basic dimensions with US quarter for size reference.

The larger D45V1E2Fx versions take up twice the area at 0.5″ × 0.6″, but they are thinner and, more importantly, offer two extra pins, including a precision enable input that can be used to set a cutoff voltage.

D45V1E2Fx step-down voltage regulator pinout.

We have a 1 MΩ pull-up resistor on the enable input, which means that if you pull that line low, you will lose about 1 μA per volt on your input. At higher input voltages, this current is higher than the quiescent (no-load) current the regulator consumes, so if you are just powering a microcontroller with a low idle or sleep current, you might be better off just using those low-power states to save energy, but if your load continuously draws more current, the shutdown feature could help prevent over-discharging your battery.

As with our other electronics products, we make these at our Las Vegas, Nevada headquarters, so we can quickly customize them for other output voltages besides our stock versions of 3.3 V, 5 V, and 12 V (depending on the customization, we can usually do custom production runs for setup fees starting around $250).

Introductory special discount! Try some out for only $3.33 each using our introductory special coupon, D45V1EXINTRO (limit 3 per version)!

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	12V, 100mA Step-Down Voltage Regulator D45V1E2F12
	5V, 100mA Step-Down Voltage Regulator D45V1E2F5
	3.3V, 100mA Step-Down Voltage Regulator D45V1E2F3
	12V, 100mA Step-Down Voltage Regulator D45V1E1F12
	5V, 100mA Step-Down Voltage Regulator D45V1E1F5
	3.3V, 100mA Step-Down Voltage Regulator D45V1E1F3

We are pleased to announce that Pololu is now an authorized Dobot distributor, and our first offering from their catalog is a robot arm that we are especially excited about: the Dobot MG400 Desktop Cobot Robotic Arm. The Dobot MG400 is a departure from products typically available from Pololu. While the 8 kg (17 lb) unit is small for the collaborative robot world, it is much larger than typical Pololu products, and the cost is correspondingly higher as well. However, the price is still very competitive for what the robot arm offers, as the high ±0.05 mm positional repeatability, collision detection, and drag-to-teach ability make this cobot a compelling option for serious automation applications. With a footprint of 19 cm (7.5 in) square, the small size and low cost also make the Dobot MG400 accessible to many education and research applications that need more than a toy or hobby product. The following video shows off some of the arm’s features:

The Dobot MG400 has a maximum reach of 44 cm and can rotate through 320°, and it can lift payloads up to 500 g (18 oz). Dobot makes a sliding track module that substantially expands the operating envelope of this robot and a vision system, which are also available through Pololu (product pages for those are coming soon).

Motion range of the Dobot MG400 Desktop Cobot Robotic Arm, profile view.

Motion range of the Dobot MG400 Desktop Cobot Robotic Arm, top view.

The picture below shows all of the accessories included with the MG400:

Accessories included with the Dobot MG400 Desktop Cobot Robotic Arm.

Please note that this arm does not include any grippers, but it does include a general-purpose flange for mounting end effectors that can be purchased separately from Dobot or other suppliers, or you can 3D print your own. A suction nozzle is included, but it requires an external air supply (compressor not included) to function.

The MG400 can be programmed a variety of ways, including through drag-to-teach positioning, a graphical programming interface, and Lua scripting. The controller in the base has plenty of I/O that makes it easy to integrate the robot into a bigger system.

The pictures below show example MG400 applications with custom 3D-printed electromagnet end effectors used to manipulate Micro Metal Gearmotors for packaging and testing.

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Dobot MG400 Desktop Cobot Robotic Arm