More new current sensors!

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