ACS72981ELRATR-200B5 Current Sensor Large Carrier -200A to +200A, 5V

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

Pololu 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; Pololu 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 mO, 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 and 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:

	PololuItem #	Part Suffix	Supply Voltage(V)	Current Range		Sensitivity @Nominal Vcc(mV/A)	Zero Point @Nominal Vcc(V)	Size
Large Carrier	#5270	050B3	3.0 to 3.6(3.3 nominal)	Bidirectional	±50 A	26.4	1.65	1.4"×1.2"
	#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"
	#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

Details for item #5282

ACS72981ELRATR-200B5 Current Sensor Large Carrier -200A to +200A, 5V, bottom view.

ACS72981 Current Sensor Large Carrier.

This large carrier features the ACS72981ELRATR-200B5, which is intended for nominal 5 V operation and is designed for bidirectional input current from -200 A to +200 A. This version can be visually distinguished from the other versions by the “5V B20” printed on the bottom side, as shown in the left picture above.

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 10 mV × (VCC/5 V) per amp of input current, with positive current increasing the output voltage and negative current decreasing the output voltage:

VIOUT=VCC2+0.01VA⋅VCC5V⋅IP=VCC⋅(12+IP500A)" role="presentation" style="position: relative;">VIOUT=VCC2+0.01VA·VCC5V·IP=VCC·(12+IP500A)VIOUT=VCC2+0.01VA·VCC5V·IP=VCC·(12+IP500A)

IP=500A⋅(VIOUTVCC–12)" role="presentation" style="position: relative;">IP=500A·(VIOUTVCC–12)IP=500A·(VIOUTVCC–12)

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).

Comparison of the Pololu current sensor carriers

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

	ACS711 CurrentSensor Carriers	ACS71240 CurrentSensor Carriers	ACS724 CurrentSensor Carriers	ACS37220Current SensorCompact Carriers	ACS37220Current SensorLarge Carriers	ACS72981Current SensorCompact Carriers	ACS72981Current SensorLarge Carriers
Sensor IC	AllegroACS711KEXT	AllegroACS71240	AllegroACS724LLCTR	Allegro ACS37220		Allegro ACS72981xLR
Vcc range (V)	3.0–5.5	3.3V versions: 3.0–3.65V versions: 4.5–5.5	4.5–5.5	3.3V versions: 3.15–3.455V versions: 4.5–5.5		3.3V versions: 3.0–3.65V versions: 4.5–5.5
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/A5V Bidirectional:±10 A / 200 mV/A±30 A / 66 mV/A±50 A / 40 mV/A5V 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/A0–?10 A / 400 mv/A0–?20 A / 200 mv/A0–?30 A / 133 mV/A	3.3V Bidirectional:±100 A / 13.2 mV/A±150 A / 8.8 mV/A5V 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/A5V 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/A3.3V Unidirectional:(1)0–?50 A / 52.8 mv/A0–?100 A / 26.4 mv/A0–?150 A / 17.6 mv/A0–?200 A / 13.2 mv/A5V Bidirectional:(2)±50 A / 40 mV/A±100 A / 20 mV/A±150 A / 13.3 mV/A±200 A / 10 mV/A5V Unidirectional:(2)0–?100 A / 40 mv/A0–?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/A3.3V Unidirectional:(1)0–?50 A / 52.8 mv/A0–?100 A / 26.4 mv/A0–?150 A / 17.6 mv/A0–?200 A / 13.2 mv/A5V Bidirectional:(2)±50 A / 40 mV/A±100 A / 20 mV/A±150 A / 13.3 mV/A±200 A / 10 mV/A5V Unidirectional:(2)0–?100 A / 40 mv/A0–?150 A / 26.7 mv/A
IC path resistance	0.6 mO	0.6 mO	0.6 mO	0.1 mO		0.2 mO
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
Max bandwidth	100 kHz	120 kHz	120 kHz(3)	150 kHz		250 kHz
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"
Overcurrent fault output				User-configurable threshold
Differential sensing
Non-ratiometric output
(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.

Dimensions

General specifications

Identifying markings

Notes:

1

At VCC = 5 V.

2

Typical.

File downloads

• Dimension diagrams of the ACS72981xLR Current Sensor Carriers (400k pdf)

• 3D model of the ACS72981xLR Current Sensor Large Carriers (3MB step)

• Drill guide for the ACS72981xLR Current Sensor Large Carriers (19k dxf)

  This DXF drawing shows the locations of all of the board’s holes.

Recommended links

• ACS72981 datasheet

• Allegro Application Note AN296169: Characterizing System Bandwidth in Complex Current Sensor Applications

  This is the application note referenced on page 16 of the ACS724 datasheet, page 22 of the ACS71240 datasheet, and page 42 of the ACS72981xLR datasheet. The ACS720 is used validate the test methods presented, but these same methods and principles would also apply to the ACS724, ACS71240, and ACS72981.

• Allegro product page for the ACS72981 Hall-based Current Sensor

  Allegro product page for the ACS72981, where you can find additional application notes and other resources.