ACS72981LLRATR-100B5 Current Sensor Large Carrier -100A to +100A, 5V

Pololu item #: 5274
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant

Price break Unit price (US$)
1 12.95
5 11.91
25 10.96
100 10.08


backorders allowed

This is the large version of a simple carrier for Allegro’s ACS72981LLRATR-100B5 Hall effect-based, electrically isolated current sensor, which offers a low-resistance (~0.2 mΩ) current path and a high 250 kHz bandwidth for fast response times.

Part Suffix Range Supply Voltage Sensitivity @ 5 V Zero Point @ 5 V Size
100B5 ±100 A (bidirectional) 4.5 V to 5.5 V 20 mV/A 2.5 V 1.4″×1.2″

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

 Description Specs (12) Pictures (14) Resources (6) FAQs (0) On the blog (0) 

Overview

ACS72981 Current Sensor Compact Carrier (top) and Large Carrier (bottom) size comparison.

We are offering these breakout boards with support from Allegro Microsystems as an easy way to use or evaluate their ACS72981xLR Hall effect-based, electrically isolated current sensors; we therefore recommend careful reading of the ACS72981 datasheet before using this product. The following list details some of the sensor’s key features:

  • Hall effect-based sensor with electrically isolated current path allows the sensor to be inserted anywhere along the current path and to be used in applications that require electrical isolation.
  • Differential Hall sensing rejects common-mode fields, so the orientation of the sensor relative to uniform external magnetic fields (e.g. the Earth’s magnetic field) has less effect on the measurement.
  • The conductive path internal resistance is typically 0.2 mΩ, and the PCB is made with 6 layers of 2-oz copper, so very little power is lost in the module.
  • High-bandwidth 250 kHz analog output voltage proportional to AC or DC currents
  • Less than 2 µs response time.
  • Integrated digital temperature compensation circuitry allows improved accuracy over the full operating temperature range.
  • Carrier boards, available in compact and large sizes, offer a variety of ways to insert it into the current path along with 0.1″-pitch (breadboard-compatible) power, ground, and output pins.
  • 3.3V and 5V versions available.
  • Unidirectional and bidirectional versions available.

The connection points are labeled on the bottom silkscreen. The silkscreen also shows the direction that is interpreted as positive current flow via the +i arrow.

The following table lists the available ACS72981 carrier options:

Pololu
Item #
Part Suffix Supply Voltage
(V)
Current Range Sensitivity @
Nominal Vcc
(mV/A)
Zero Point @
Nominal Vcc
(V)
Size Price


Large Carrier
#5270 050B3 3.0 to 3.6
(3.3 nominal)
Bidirectional ±50 A 26.4 1.65 1.4″×1.2″ $12.95
#5273 100B3 ±100 A 13.2
#5277 150B3 ±150 A 8.8
#5272 050U3 Unidirectional 0-50 A 52.8 0.33
#5275 100U3 0-100 A 26.4
#5279 150U3 0-150 A 17.6
#5283 200U3 0-200 A 13.2
#5271 050B5 4.5 to 5.5
(5 nominal)
Bidirectional ±50 A 40 2.5
#5274 100B5 ±100 A 20
#5278 150B5 ±150 A 13.3
#5282 200B5 ±200 A 10
#5276 100U5 Unidirectional 0-100 A 40 0.5
#5280 150U5 0-150 A 26.7


Compact Carrier
#5250 050B3 3.0 to 3.6
(3.3 nominal)
Bidirectional ±50 A 26.4 1.65 0.7″×0.8″ $9.95
#5253 100B3 ±100 A 13.2
#5257 150B3 ±150 A 8.8
#5252 050U3 Unidirectional 0-50 A 52.8 0.33
#5255 100U3 0-100 A 26.4
#5259 150U3 0-150 A 17.6
#5263 200U3 0-200 A 13.2
#5251 050B5 4.5 to 5.5
(5 nominal)
Bidirectional ±50 A 40 2.5
#5254 100B5 ±100 A 20
#5258 150B5 ±150 A 13.3
#5262 200B5 ±200 A 10
#5256 100U5 Unidirectional 0-100 A 40 0.5
#5260 150U5 0-150 A 26.7

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

Details for item #5274

ACS72981LLRATR-100B5 Current Sensor Large Carrier -100A to +100A, 5V, bottom view.

ACS72981 Current Sensor Large Carrier.

This large carrier features the ACS72981LLRATR-100B5, which is intended for nominal 5 V operation and is designed for bidirectional input current from -100 A to +100 A. This version can be visually distinguished from the other versions by the “5V B10” printed on the bottom side, as shown in the left picture above.

Part Suffix Range Supply Voltage Sensitivity @ 5 V Zero Point @ 5 V Size
100B5 ±100 A (bidirectional) 4.5 V to 5.5 V 20 mV/A 2.5 V 1.4″×1.2″

A compact carrier is also available for this sensor IC for more space-constrained applications or to evaluate the IC’s performance with a smaller PCB area for thermal dissipation.

Using the sensor

This sensor has five required connections: the input current (IP+ and IP-), logic power (VCC and GND), and the sensor output (VIOUT).

The sensor requires a supply voltage of 4.5 V to 5.5 V to be connected across the VCC and GND pads, which are labeled on the bottom silkscreen. The sensor outputs a ratiometric analog voltage on VIOUT that is centered at VCC/2 and changes by 20 mV × (VCC/5 V) per amp of input current, with positive current increasing the output voltage and negative current decreasing the output voltage:

``V_"IOUT" = V_"CC" / 2 + 0.02 text(V)/text(A) * V_"CC" / (5 text(V)) * I_"P" = V_"CC" * (1/2 + I_"P" / (250 text(A)))``

``I_"P" = 250 text(A) * (V_"IOUT" / V_"CC" – 1/2)``

The VIOUT, VCC, and GND pins work with 0.1″-pitch header pins and are compatible with standard solderless breadboards.

You can insert the board into your current path in a variety of ways. The largest through-holes are 8.4 mm in diameter with 20 mm spacing. These can be used with 5/16″ or M8 screws for attaching various types of lugs or solderless ring terminals, or thick wires up to 2 AWG can be soldered directly to the board. The slots near the edge of the board can accommodate a 4-pin terminal block or other connector with a pitch between 7.5 mm and 9.5 mm. Examples of these kinds of connections are shown in the pictures below. Holes with 0.1″, 3.5 mm, and 5 mm spacing are also available for connecting male header pins or terminal blocks, but please note that these smaller connection options are generally not suitable for high currents like those this sensor is intended for.

Warning: This product is intended for use below 30 V. Working with higher voltages can be extremely dangerous and should only be attempted by qualified individuals with appropriate equipment and experience.

Schematic and dimension diagrams

ACS72981 Current Sensor Carrier schematic diagram.

The dimension diagram is available as a downloadable PDF (400k pdf).

Real-world power dissipation considerations

Thermal image of a high-current test of a Pololu current sensor carrier (not necessarily this product).

Depending on the version, the ACS72981 can measure up to ±200 A, but its datasheet specifies an absolute maximum continuous current of 120 A. Furthermore, the sensor chip can overheat at lower currents. In our tests, we found that our ACS72981 carrier boards could conduct 60 A continuously while staying well below the thermal limit for the IC. Our tests were conducted at approximately 25°C ambient temperature with no forced air flow.

The actual current you can pass through the sensor will depend on how well you can keep it cool. The carrier’s printed circuit board is designed to help with this by drawing heat out of the sensor chip. Solid connections to the current path pins (such as with thick soldered wires or large, tightly-secured lugs) can also help reduce heat build-up in the sensor and carrier board.

Warning: Exceeding temperature or current limits can cause permanent damage to the sensor. If you are measuring an average continuous current greater than 50 A, we strongly recommend that you monitor the sensor’s temperature and look into additional cooling if necessary.

This product can get hot enough to burn you long before the chip overheats. Take care when handling this product and other components connected to it.

Comparison of the Pololu current sensor carriers

We have a variety of current sensors available with different ranges, sensitivities, and features. The table below summarizes our selection of active and preferred options:


ACS711 Current
Sensor Carriers
ACS71240 Current
Sensor Carriers
ACS724 Current
Sensor Carriers
ACS37220
Current Sensor
Compact Carriers
ACS37220
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
Sensor IC Allegro
ACS711KEXT
Allegro
ACS71240
Allegro
ACS724LLCTR
Allegro ACS37220 Allegro ACS72981xLR Allegro CT432/CT433
Sensing technology Hall effect Hall effect Hall effect Hall effect Hall effect XtremeSense™ TMR
(tunneling magnetoresistance)
Logic voltage range (V) 3.0–5.5 3.3V versions: 3.0–3.6
5V versions: 4.5–5.5
4.5–5.5 3.3V versions: 3.15–3.45
5V versions: 4.5–5.5
3.3V versions: 3.0–3.6
5V versions: 4.5–5.5
3.3V versions: 3.0–3.6
5V versions: 4.75–5.5
Current range / sensitivity 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:(1)
±50 A / 26.4 mV/A
±100 A / 13.2 mV/A
±150 A / 8.8 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)
0–⁠100 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

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)
0–⁠100 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 path resistance 0.6 mΩ 0.6 mΩ 0.6 mΩ 0.1 mΩ 0.2 mΩ 1 mΩ
PCB 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
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 100 kHz 120 kHz 120 kHz(3) 150 kHz 250 kHz 1 MHz
Size 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″ 0.8″ × 1.1″ 1.4″ × 1.2″
Overcurrent fault output User-configurable threshold
Common-mode field rejection
Non-ratiometric output
1-piece price $3.49 $3.95 $6.95$7.49 $4.95 $7.95 $9.95 $12.95 $8.95 $12.95

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

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