This board is a simple carrier of Allegro’s ±30A ACS714 Hall effect-based linear current sensor, which offers a low-resistance (~1.2 mΩ) current path and electrical isolation up to 2.1 kV RMS. This version accepts a bidirectional current input with a magnitude up to 30 A and outputs a proportional analog voltage (66 mV/A) centered at 2.5 V with a typical error of ±1.5%. It operates from 4.5 V to 5.5 V and is intended for use in 5 V systems.
This current sensor is a carrier board or breakout board for Allegro’s ACS714LLCTR-30A-T Hall effect-based linear current sensor; we therefore recommend careful reading of the ACS714 datasheet (701k pdf) before using this product. The sensor operates at 5 V and has an output sensitivity of 66 mV/A. The board ships fully populated with its SMD components, including the ACS714, as shown in the product picture. The following list details some of the sensor’s key features:
- Designed for bidirectional input current from -30 A to 30 A (though the robust sensor IC can survive up to five times the overcurrent condition).
- Conductive path internal resistance is typically 1.2 mΩ, and the PCB is made with 2-oz copper, so very little power is lost in the board.
- Use of a Hall effect sensor means the IC is able to electrically isolate the current path from the sensor’s electronics (up to 2.1 kV RMS), which allows the sensor to be inserted anywhere along the current path and to be used in applications that require electrical isolation.
- 80 kHz bandwidth that can optionally be decreased by adding a capacitor across the board pins marked “filter”.
- High accuracy and reliability: typical total output error of ±1.5% at room temperature with factory calibration, an extremely stable output offset voltage, and almost zero magnetic hysteresis.
- Automotive-grade operating temperature range of -40°C to 150°C.
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 version is marked with a red X. We also sell a 30A unidirectional version and a ±5A bidirectional version of this board; you can distinguish these versions by reading the text on the IC or by looking at the color of the X on the bottom silkscreen.