# ACS724 Current Sensor Carrier -2.5A to +2.5A

**Type:** Product page · **SKU:** POLOLU-4040 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia)
**Page:** https://core-electronics.com.au/acs724-current-sensor-carrier-25a-to-25a.html ([markdown](https://core-electronics.com.au/acs724-current-sensor-carrier-25a-to-25a.html.md))

This board is a simple carrier of Allegro’s bidirectional ±2.5A ACS724LLCTR-2P5AB Hall effect-based linear current sensor, which offers a low-resistance...

## Pricing

- **Price:** $16.35 (inc GST) — $14.86 AUD, exc GST
- **Quantity discounts:** 10+ $14.27 (exc GST) · 25+ $13.83 (exc GST)

## Availability & dispatch

- In stock, ships same business day if ordered before 2PM (Australia/Sydney).
- We can dispatch 3 today, and up to 200 more in 4–7 days.

## Description

Pololu is 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; Pololu therefore recommends careful reading of the [ACS724 datasheet](https://core-electronics.com.au/attachments/localcontent/acs724-datasheet_14915e2ac13.pdf) 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 1.2 mO, and the PCB is made with 2-oz or 4-oz copper, depending on the sensor version, so very little power is lost in the module.
- High-bandwidth 120 kHz analog output voltage proportional to AC or DC currents.
- Typical 4 µs response time.
- Optional FILTER pin simplifies bandwidth limiting for better noise reduction and improved resolution at lower frequencies.
- Integrated digital temperature compensation circuitry allows for near closed loop accuracy over temperature in an open loop sensor.
- Automotive-grade operating temperature range of -40°C to 150°C.
- 0.7"×0.8" carrier board offers a variety of ways to insert it into the current path along with 0.1"-pitch (breadboard-compatible) power, ground, and output pins.
- Unidirectional and bidirectional versions available.

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.

This carrier features the ACS724LLCTR-2P5AB, which operates at 5 V and is designed for bidirectional input current from -2.5 A to +2.5 A. This version can be visually distinguished from the other versions by the writing on the IC as shown in the pictures above.

When Vcc is 5 V, the output voltage is centered at 2.5 V and changes by 800 mV per amp of input current, with positive current increasing the output voltage and negative current decreasing the output voltage.

This board ships assembled with all surface mount components, and a 3×1 strip of [0.1" header pins](https://core-electronics.com.au/0-100-2-54-mm-breakaway-male-header-1x40-pin-straight.html) 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:

VIOUT=Zero Point+Sensitivity⋅IP" role="presentation" style="position: relative;">VIOUT=Zero Point+Sensitivity·IP

IP=VIOUT–Zero PointSensitivity" role="presentation" style="position: relative;">IP=VIOUT–Zero PointSensitivity

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](https://core-electronics.com.au/0-100-2-54-mm-breakaway-male-header-1x40-pin-straight.html) 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**

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

**Comparison of the Pololu current sensor carriers**

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

**Dimensions**

| Size: | 0.7" × 0.8" |
|---|---|
| Weight: | 1.1 g |

**General specifications**

| Current sense: | 800 mV/A[1](https://core-electronics.com.au/#note1) |
|---|---|
| Minimum logic voltage: | 4.5 V |
| Maximum logic voltage: | 5.5 V |
| Supply current: | 14 mA[2](https://core-electronics.com.au/#note2) |
| Current range: | -2.5A to +2.5A (bidirectional 2.5A), 5V |
| Current sensor: | Allegro ACS724LLCTR-2P5AB |

**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**

- **Dimension diagram of the ACS724 Current Sensor Carrier (1MB pdf)**
- **3D model of the ACS724 Current Sensor Carrier (3MB step)**
- **Drill guide for ACHS-712x Current Sensor Carriers (17k dxf)**
    
    This DXF drawing shows the locations of all of the board’s holes. The through-hole sizes and locations in this file also apply to cs01b versions of the PCB, though some of the via locations are different.

**Recommended links**

- **[ACS724 datasheet](https://core-electronics.com.au/attachments/localcontent/acs724-datasheet_14915e2ac13.pdf)**
- **[Allegro Application Note AN296169: Characterizing System Bandwidth in Complex Current Sensor Applications](https://www.allegromicro.com/en/insights-and-innovations/technical-documents/hall-effect-sensor-ic-publications/an-effective-method-for-characterizing-system-bandwidth-an296169)**
    
    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 to 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 ACS724 Hall-based Current Sensor](https://www.allegromicro.com/en/products/sense/current-sensor-ics/zero-to-fifty-amp-integrated-conductor-sensor-ics/acs724-5)**
    
    Allegro product page for the ACS724, where you can find additional application notes and other resources.

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/P/O/POLOLU-4040-1.jpg)