ACS712ELCTR-05B Hall Effect Current Sensor

The ACS712ELCTR-05B is a fully integrated, Hall-effect-based linear current sensor IC from Allegro MicroSystems, designed for economical and precise AC or DC current sensing in industrial, automotive, commercial, and communication systems. The device consists of a precise, low-offset, linear Hall sensor circuit with a copper conduction path located near the surface of the die. Current flowing through this copper path generates a magnetic field that is sensed by the integrated Hall IC and converted into a voltage proportional to the current. This architecture provides galvanic isolation between the current path and the sensor output, with a rated isolation voltage of 2.1 kVRMS, allowing the low-voltage measurement circuit to remain electrically separated from the high-voltage or high-current conductor.

The ACS712ELCTR-05B is optimized for bidirectional current sensing over a ±5A range and provides a sensitivity of 185mV/A. Its output is ratiometric, meaning the zero-current output voltage is nominally 50% of VCC, and the output swings above or below this midpoint depending on current direction. The device operates from a single 4.5V to 5.5V supply, draws a typical quiescent current of 10mA (13mA maximum), and offers a bandwidth of 80kHz with a response time of approximately 5µs. Accuracy is specified at ±1.5% at room temperature, and the internal chopper-stabilized BiCMOS Hall IC is programmed for accuracy after packaging.

The sensor is housed in a compact SOIC-8 surface-mount package measuring approximately 4.9mm × 3.9mm × 1.5mm and weighing about 0.1g for the bare IC. It is commonly sold as a breakout module (approximately 31mm × 13mm) that adds a decoupling capacitor and a 3-pin header (VCC, GND, OUT) for easy connection to microcontrollers. The device operates over a temperature range of -40°C to +85°C. Typical applications include motor control, power supply monitoring, load detection, overcurrent protection, and energy management in Arduino, ESP32, and industrial control systems.