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ACS71240KEXBLT-010B3 Current Sensor Carrier -10A to +10A, 3.3V
This board is a simple carrier of Allegro’s ACS71240KEXBLT-010B3 Hall effect-based linear current sensor, which offers a low-resistance (~0.6 mΩ) current path and a high 120 kHz bandwidth for fast response times.
Part Suffix | Range | Supply Voltage | Sensitivity | Zero Point | Fault Trip Level |
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010B3 | ±10 A (bidirectional) | 3.0 V to 3.6 V | 132 mV/A | 1.65 V | ±10 A |
Alternatives available with variations in these parameter(s): version Select variant…
Description | Specs (12) | Pictures (11) | Resources (6) | FAQs (0) | On the blog (0) |
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Overview
We are offering these breakout boards with support from Allegro Microsystems as an easy way to use or evaluate their ACS71240 Hall effect-based linear current sensors; we therefore recommend careful reading of the ACS71240 datasheet before using this product. The following list details some of the sensor’s key features:
- 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 0.6 mΩ, and the PCB is made with 2-oz copper, so very little power is lost in the module.
- Use of a Hall effect sensor means the IC is able to electrically isolate the current path from the sensor’s electronics, which allows the sensor to be inserted anywhere along the current path and to be used in applications that require electrical isolation.
- High-bandwidth 120 kHz analog output voltage proportional to AC or DC currents.
- Overcurrent fault output with 1.5 µs response time indicates when the current exceeds the optimized sensing range.
- Output is not ratiometric (i.e. the zero point and sensitivity are independent of the actual supply voltage), which provides immunity from noisy supplies.
- 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 125°C.
- 0.7″×0.8″ carrier board offers a variety of ways to insert it into the current path and 0.1″-pitch (breadboard compatible) power, ground, and output pins.
The pads are labeled on the bottom silkscreen. The silkscreen also shows the direction that is interpreted as positive current flow via the +i arrow.
Details for item #5240
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This carrier features the ACS71240KEXBLT-010B3, which is intended for operation around 3.3 V and is designed for bidirectional input current from -10 A to +10 A. This version can be visually distinguished from the other versions by the “3V3 B10” printed on the bottom side, as shown in the left picture above.
Part Suffix | Range | Supply Voltage | Sensitivity | Zero Point | Fault Trip Level |
---|---|---|---|---|---|
010B3 | ±10 A (bidirectional) | 3.0 V to 3.6 V | 132 mV/A | 1.65 V | ±10 A |
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 3.0 V to 3.6 V to be connected across the VCC and GND pads, which are labeled on the bottom silkscreen. The sensor outputs an analog voltage on VIOUT that is centered at 1.65 V and changes by 132 mV per amp of input current, with positive current increasing the output voltage and negative current decreasing the output voltage:
``text(VIOUT) = 1.65 V + 0.132 V/A * text(IP)``
``text(IP) = (text(VIOUT) – 1.65 V) / (0.132 V/A) = (text(VIOUT) – 1.65 V) * 7.58 A/V ``
The output is not ratiometric, so the zero point and sensitivity are independent of the actual supply voltage.
The optional FAULT pin is normally at VCC and is pulled low when the IP current magnitude exceeds 10 A in either direction. This pin only asserts while the fault condition is present (it is not latched).
The FAULT, 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. Holes with 0.1″, 3.5 mm, and 5 mm spacing are available as shown in the diagram above for connecting male header pins or terminal blocks. For high-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. The pictures below show some of the possible connection options:
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
ACS72140 current sensor carrier schematic diagram. |
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The dimension diagram is available as a downloadable PDF (274k 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 |
ACS72981 Current Sensor Carriers |
|
---|---|---|---|---|
Sensor IC: | Allegro ACS711KEXT |
Allegro ACS71240 |
Allegro ACS724LLCTR |
Allegro ACS72981xLR |
Vcc range: | 3 V–5.5 V | 3.3V versions: 3.0 V–3.6 V 5V versions: 4.5 V–5.5 V |
4.5 V–5.5 V | 3.3V versions: 3.0 V–3.6 V 5V versions: 4.5 V–5.5 V |
Current range / sensitivity: |
Bidirectional:(1) ±15.5 A / 90 mV/A ±31 A / 45 mV/A |
Bidirectional 3.3V: ±10 A / 132 mV/A ±50 A / 26.4 mV/A Unidirectional 5V: 0–50 A / 80 mv/A |
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 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 |
Bidirectional 3.3V:(1) ±50 A / 26.4 mV/A ±150 A / 8.8 mV/A Unidirectional 3.3V:(1) 0–50 A / 52.8 mv/A 0–100 A / 26.4 mv/A Bidirectional 5V:(2) ±50 A / 40 mV/A Unidirectional 5V:(2) 0–100 A / 40 mv/A |
IC path resistance: | 0.6 mΩ | 0.6 mΩ | 0.6 mΩ | 0.2 mΩ |
Max bandwidth: | 100 kHz | 120 kHz | 120 kHz(3) | 250 kHz |
Size: | 0.7″ × 0.8″ | 0.7″ × 0.8″ | 0.7″ × 0.8″ | 0.7″ × 0.8″ |
Overcurrent fault output | ||||
Differential sensing | ||||
Non-ratiometric output | ||||
1-piece price: | $3.49 | $3.95 | $6.95 – $7.49 | $9.95 |
(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. |