Current Sensors

Our bidirectional and unidirectional current sensors are a simple way to gain fundamental insight into the performance of your system. You can use them for closed-loop torque control of actuators, tracking power consumption over time, load detection, over-current fault protection, or even as inexpensive current probes for an oscilloscope. We are offering these breakout boards with support from Allegro Microsystems.

These current sensors output an analog voltage that varies linearly with the current passing through them and offer full electrical isolation of the current path from the sensor’s electronics. This method of sensing means the sensor can be inserted anywhere into the current path, including on the high side, and because their current path resistance is on the order of 1 mΩ or less, they have minimal effect on the rest of the system.

All of our current sensor carrier boards (also called breakout boards) feature multiple options for making connections. For low-current applications, they all include at least one pair of through-holes compatible with 0.1″ male header pins, and for higher-current applications, the larger through-holes can be used for either soldering wires directly to the board or connecting solderless ring terminals.

The comparison table below summarizes our selection of active and preferred current sensors:



CT220 Contactless
Current Sensor
Carriers
ACS3704x
Current Sensor
Micro Carriers
ACS3704x
Current Sensor
Compact Carriers
ACS711 Current
Sensor Carriers
ACS71240 Current
Sensor Carriers
ACS724 Current
Sensor Carriers
ACS37030
Current Sensor
Compact Carriers
ACS37220
Current Sensor
Compact Carriers
Allegro Sensor CT220xMV-HS5 ACS3704x ACS711KEXT ACS71240 ACS724LLCTR ACS37220 ACS37030
Sensing technology XtremeSense™
TMR (tunneling magnetoresistance)
Hall effect Hall effect Hall effect Hall effect Hall effect + inductive coil Hall effect
Logic voltage range 2.7–5.5 V 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 3.0–3.6 V 3.3V ver: 3.15–3.45 V
5V ver: 4.5–5.5 V
Family current range 10–800 A 10–30 A 15.5–31 A 10–50 A 2.5–50 A 20–65 A 100–200 A
Range/sensitivity of individual versions (2)
±1.5 mT / 1500 mV/mT
±15 mT / 150 mV/mT
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:
±20 A / 66 mV/A
±65 A / 20.3 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
IC current path resistance N/A 1.6 mΩ 0.6 mΩ 0.6 mΩ 0.6 mΩ 0.7 mΩ 0.1 mΩ
PCB N/A 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(3)
2 layers,
2-oz copper
2 layers,
2-oz copper
Max bandwidth 30 kHz 150 kHz 100 kHz 120 kHz 120 kHz(4) 5 MHz 150 kHz
Size 0.4″ × 0.62″ 0.3″ × 0.4″ 0.7″ × 0.8″ 0.7″ × 0.8″ 0.7″ × 0.8″ 0.7″ × 0.8″ 0.7″ × 0.8″ 0.7″ × 0.8″
Overcurrent
fault output
User-configurable threshold
Common-mode field rejection
Nonratiometric output
1-piece price $4.95 $4.15$4.69 $4.45$4.99 $4.85 $5.25 $9.95$11.49 $11.95 $6.95

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: 50A version of this carrier uses 4-oz copper PCB; all other versions of this carrier use 2-oz copper.
Note 4: Bandwidth can be reduced by adding a filter capacitor.

ACS37030
Current Sensor
Compact Carriers
ACS37030
Current Sensor
Large Carriers
CT432/CT433 TMR
Current Sensor
Compact Carriers
CT432/CT433 TMR
Current Sensor
Large Carriers
ACS72981
Current Sensor
Compact Carriers
ACS72981
Current Sensor
Large Carriers
ACS37220
Current Sensor
Compact Carriers
ACS37220
Current Sensor
Large Carriers
Allegro Sensor ACS37030 CT432/CT433 ACS72981xLR ACS37220
Sensing technology Hall effect + inductive coil XtremeSense™ TMR
(tunneling magnetoresistance)
Hall effect Hall effect
Logic voltage range 3.0–3.6 V 3.3V versions: 3.0–3.6 V
5V versions: 4.75–5.5 V
3.3V versions: 3.0–3.6 V
5V versions: 4.5–5.5 V
3.3V versions: 3.15–3.45 V
5V versions: 4.5–5.5 V
Family current range 20–65 A 20–70 A 50–200 A 100–200 A
Range/sensitivity of individual versions 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:
±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
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:
±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
IC current path resistance 0.7 mΩ 1 mΩ 0.2 mΩ 0.1 mΩ
PCB 2 layers,
2-oz copper
6 layers,
2-oz copper
2 or 4 layers(3),
2-oz copper
6 layers,
2-oz copper
6 layers,
2-oz copper
6 layers,
2-oz copper
2 layers,
2-oz copper
6 layers,
2-oz copper
Max bandwidth 5 MHz 1 MHz 250 kHz 150 kHz
Size 0.7″ × 0.8″ 1.4″ × 1.2″ 0.8″ × 1.1″ 1.4″ × 1.2″ 0.7″ × 0.8″ 1.4″ × 1.2″ 0.7″ × 0.8″ 1.4″ × 1.2″
Overcurrent
fault output
User-configurable threshold
Common-mode field rejection
Nonratiometric output
1-piece price $11.95 $14.95 $12.95 $16.95 $13.95 $16.95 $6.95 $10.95

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: 50A and higher versions of this carrier use a 4-layer PCB; all other versions of this carrier use a 2-layer PCB.

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

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

Subcategories

Monitor voltage, current, power, and other parameters in AC and DC systems with these boards featuring Allegro’s ACS37800KMACTR-030B3-I2C isolated power monitoring IC. They provide bidirectional current measurements from -30 A to +30 A and can be configured to measure voltages up to 480 VRMS nominal (±980 V peak).

These boards are simple carriers of Allegro’s contactless current sensors, which measure the magnetic field of the current flowing through a nearby conductor without needing to be connected in series with the circuit. They output an analog voltage proportional to the magnetic field that with simple calibration can be converted into an accurate current measurement.

These boards are simple carriers of Allegro’s high-dV/dt, high bandwidth (1 MHz) CT432/CT433 tunneling magneto­resistance (TMR) current sensors, which output an analog voltage proportional to the current passing through them. They offer common-field mode rejection, a low-resistance (~1 mΩ) current path, and overcurrent fault. 3.3V and 5V versions are available.

These boards are simple carriers of Allegro’s high-current ACS72981 Hall effect-based, galvanically isolated current sensors, which output an analog voltage proportional to the current passing through them. They offer differential sensing, a low-resistance (~0.2 mΩ) current path, and a high 250 kHz bandwidth. 3.3V and 5V versions are available.

These boards are simple carriers of Allegro’s high-current ACS37220 Hall effect-based, galvanically isolated current sensors, which output an analog voltage proportional to the current passing through them. They offer differential sensing, an extra-low-resistance (~0.1 mΩ) current path, and configurable overcurrent fault. 3.3V and 5V versions are available.

These boards are simple carriers of Allegro’s 3.3V ACS37030 DC to 5 MHz bandwidth, galvanically isolated current sensors, which output an analog voltage proportional to the current passing through them. They offer differential sensing for higher accuracy, a low-resistance (~0.7 mΩ) current path, and a zero-current reference output.

These boards are simple carriers of Allegro’s 5V ACS724 Hall effect-based, galvanically isolated current sensors, which output an analog voltage proportional to the current passing through them. They offer differential sensing for higher accuracy and a low-resistance (~0.6 mΩ) current path.

These boards are simple carriers of Allegro’s ACS71240 Hall effect-based, galvanically isolated current sensors, which output an analog voltage proportional to the current passing through them. They offer differential sensing for higher accuracy and a low-resistance (~0.6 mΩ) current path. 3.3V and 5V versions are available.

These boards are simple carriers for Allegro’s ACS37041/2 Hall effect-based, galvanically isolated current sensor in a 5-pin SOT-23 package with ~1.6 mΩ current path resistance, differential sensing, and 150 kHz bandwidth. 3.3V and 5V versions are available with up to ±30A current range.

These boards are simple carriers of Allegro’s ACS711 Hall effect-based, galvanically isolated current sensors, which work with both 3.3V and 5V supplies and output an analog voltage proportional to the current passing through them.

These are older current sensors on clearance and will be discontinued once remaining component stock is depleted.


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