ACS724LLCTR-20AB Current Sensor Carrier -20A to +20A

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Pololu item #: 4045
Brand: Pololu
Status: Active and Preferred 
RoHS 3 compliant


This board is a simple compact carrier of Allegro’s ACS724LLCTR-20AB Hall effect-based, electrically isolated current sensor, which offers a low-resistance (~1.2 mΩ) current path and a high 120 kHz bandwidth for fast response times.

Part Suffix Range Sensitivity @ 5 V Zero Point @ 5 V Supply Voltage
20AB ±20 A (bidirectional) 100 mV/A 2.5 V 4.5 V to 5.5 V

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

Pictures

ACS724LLCTR-20AB Current Sensor Carrier -20A to +20A.

ACS724 current sensor carrier, bottom view with dimensions.

ACS724 Current Sensor Carrier pinout.

Schematic diagram of the ACS724 Current Sensor Carrier.

ACS724LLCTR-20AB Current Sensor Carrier -20A to +20A with included 0.1″ header pins.

ACS724LLCTR-20AB Current Sensor Carrier -20A to +20A, top view.

Current sensor carrier soldered with high-current wires.

Current sensor carrier with solderless ring terminal connectors (not included).

Standard packaging for the ACS724LLCTR-20AB Current Sensor Carrier -20A to +20A.




Overview

We are offering these breakout boards with support from Allegro Microsystems as an easy way to use or evaluate their ACS724LLCTR Hall effect-based, electrically isolated current sensors; we therefore recommend careful reading of the ACS724 datasheet before using this product. The following list details some of the sensor’s key features:

The pads are labeled on the bottom silkscreen, as shown in the picture to the right. The silkscreen also shows the direction that is interpreted as positive current flow via the +i arrow.

A variety of options are available with different current sensing ranges and sensitivities:

ACS724 Current Sensor Carriers
Sensitivity(1) Unidirectional range Bidirectional range
800 mV/A 0A to 5A -2.5A to +2.5A
400 mV/A 0A to 10A -5A to +5A
200 mV/A 0A to 20A -10A to +10A
133 mV/A 0A to 30A
100 mV/A -20A to +20A
66 mV/A -30A to +30A
40 mV/A -50A to +50A
1 Sensitivity shown for Vcc = 5V.

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

These versions all look very similar, and while you can distinguish them by reading the text on the IC, we also provide a white box on the bottom silkscreen where you can add your own distinguishing markings if so desired.

Details for item #4045

ACS724LLCTR-20AB Current Sensor Carrier -20A to +20A, top view.

ACS724LLCTR-20AB Current Sensor Carrier -20A to +20A with included 0.1″ header pins.

This carrier features the ACS724LLCTR-20AB, which operates at 5 V and is designed for bidirectional input current from -20 A to +20 A. This version can be visually distinguished from the other versions by the “20AB” written on the IC as shown in the pictures above.

Part Suffix Range Sensitivity @ 5 V Zero Point @ 5 V Supply Voltage
20AB ±20 A (bidirectional) 100 mV/A 2.5 V 4.5 V to 5.5 V

When Vcc is 5 V, the output voltage is centered at 2.5 V and changes by 100 mV per amp of input current, with positive current increasing the output voltage and negative current decreasing the output voltage. More generally, the sensor’s zero point and sensitivity depend on VCC as follows:

``text(Zero Point) = V_"CC" / 2``

``text(Sensitivity) = 0.1 text(V)/text(A) * (1 + ((V_"CC" – 5 text(V)) * 1.3) / (5 text(V)))``

This board ships assembled with all surface mount components, and a 3×1 strip of 0.1″ header pins is included but not soldered in.

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, and the sensor outputs an analog voltage with a linear relationship to the input current:

``V_"IOUT" = text(Zero Point) + text(Sensitivity) * I_"P"``

``I_"P" = (V_"IOUT" – text(Zero Point)) / text(Sensitivity)``

The FILTER pin lets you adjust the board’s bandwidth by adding a capacitor to ground (a ground pad has been added next to the FILTER pin for convenience) in parallel with the 1 nF capacitor that is already on the board. Without an added external filter capacitor, the bandwidth is about 90 kHz. The datasheet provides more information on how the filter capacitors affect bandwidth.

You can insert the board into your current path in a variety of ways. For low-current applications, you can solder 0.1″ male header pins to the board via the smallest pair of through-holes on the input-current side of the board. For higher-current applications, you can solder wires directly to the through-holes that best match your wires, or you can use solderless ring terminal connectors. The largest through-holes are big enough for 8 AWG wires or #6 or M3.5 screws, and the second-largest through-holes (and mounting holes) are sized for 12 AWG wires or #2 or M2 screws.

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

Schematic diagram of the ACS724 Current Sensor Carrier.

The dimension diagram is available as a downloadable PDF (1MB pdf).

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…

Dimensions

Size: 0.7″ × 0.8″
Weight: 1.1 g

General specifications

Current sense: 100 mV/A1
Minimum logic voltage: 4.5 V
Maximum logic voltage: 5.5 V
Supply current: 14 mA2
Current range: -​20A to +20A (bidirectional 20A), 5V
Current sensor: Allegro ACS724LLCTR-20AB

Identifying markings

PCB dev codes: cs01a
Other PCB markings: 0J1214, blank white box

Notes:

1
When Vcc is 5 V.
2
Max. 10 mA typical.

File downloads

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Frequently-asked questions

No FAQs available.

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