What is ACS712 Current Sensor Module? How it Works? Its Applictions -A Quick Overview

The discovery of electricity has led in a revolutionary shift in human life. We invented many innovative applications of electricity to make our daily life easier. Almost all of our equipment nowadays is powered by electricity. Current refers to the flow of charge. Depending on their functional requirements, different devices demand different amounts of current.

A sensor is required to measure current in a circuit. The ACS712 Current Sensor can be used to measure and calculate the amount of current applied to the conductor without impacting the system’s performance. We’ll talk about the ACS712 Current Sensor, how a Hall Effect-based current sensor works, its applications in this article

What is the ACS712 Current sensor?

ACS712 Current Sensor is a fully integrated, Hall-effect based linear sensor IC that can measure both DC(Direct Current) and AC(Alternating Current). This current sensor operates at a supply voltage of 5V in which output is proportional to AC or DC current. It has 2.1kVRMS voltage isolation and an integrated low-resistance current conductor

Many industrial, commercial, and communication applications use ACS712. This IC is suitable for use in automobiles. This IC can be found in motor control circuits, load detection and management, SMPS, and overcurrent fault prevention circuits, to name a few.


  • Low-noise analog signal path
  • Device bandwidth is set via the new FILTER pin
  • 5 µs output rise time in response to step input current
  • 80 kHz bandwidth
  • Total output error 1.5% at TA= 25°C
  • Small footprint, low-profile SOIC8 package
  • 2 mΩ internal conductor resistance
  • 1 kVRMSminimum isolation voltage from pins 1-4 to pins 5-8
  • 0 V, single supply operation
  • 66 to 185 mV/A output sensitivity
  • Output voltage proportional to AC or DC currents
  • Factory-trimmed for accuracy
  • Extremely stable output offset voltage
  • Nearly zero magnetic hysteresis
  • Ratiometric output from supply voltag

Pinout for ACS712 Current sensor

The ACS712 sensor module has 3 pins:

  • VCC: Power supply – 5v
  • GND: Ground
  • OUT: Analog output voltage

Based on the current sensing range, the ACS712 Sensor is divided into three types. +/-5A, +/-20A, and +/-30A are the three ranges.

How does the ACS712 Current sensor work?

Basically, a Current Sensor works on direct sensing or indirect sensing. The direct sensing uses Ohm’s law to measure the voltage drop across the wire when current flows through it. For the ACS712 current sensor, it uses indirect sensing. In order to sense current a liner, low-offset, precise Hall sensor circuit is used in this IC. This sensor was placed at the surface of the IC on a copper conduction path. 

When the applied current flows through this copper conduction path it generates a magnetic field sensed by the Hall effect sensor. Hall Sensor generates a voltage proportional to the sensed magnetic field, used to measure current. The present output current signal is read via the analogue I / O port of a microcontroller or an Arduino.

The range of the magnetic signal to the Hall sensor decides the accuracy of the device. Closer the magnetic signal higher the accuracy. ACS712 Current Sensor designed as a compact-sized, surface mount SOIC8 package. In this ACS712 Current Sensor IC, Pin-1 to Pin-4 forms the conduction path where the current is sensed. Pin-5 represents the signal ground pin. Pin-6 indicates the FILTER pin by an external capacitor to set the bandwidth. Pin-7 is the analogue output pin. Pin-8 is the power supply pin.

ACS712 Current Sensor Applications

We’ve already established a general idea of what current sensors can be used for. Because the ACS712 IC can detect both AC and DC current, it can be used in a variety of applications other than electrical appliances. It can be used in a variety of applications, including Arduino and other microcontrollers, as well as industrial, commercial, and communication applications.

Here are the common list of applications:

  • Inverters
  • SMPS
  • Battery Chargers
  • Automotive Applications like Inverters
  • Peak detection circuits, circuits to increase gain
  • Electrical load detection and management
  •  Used in industrial, commercial and communication applications.
  • Rectification application for A/D converters
  • Overcurrent fault latch, etc

Hope this blog helps you to understand basics on ACS712 Current Sensor, how a Hall Effect-based current sensor works, its applications in this article. We ,MATHA ELECTRONICS  will come back with more informative blogs.

Leave a Reply

Your email address will not be published.