ACS712ELCTR-05B-T is a high-precision Hall effect-based current sensor launched by Allegro MicroSystems, specifically designed for non-contact measurement of direct current (DC), alternating current (AC), or pulsed current. It is widely used in current monitoring scenarios requiring electrical isolation and low power consumption. Below is a detailed description of its core features and technical specifications:

Core Parameters and Functions

Measurement Range and Accuracy

Current range: ±5A (bidirectional measurement, covering positive and negative currents), suitable for current monitoring in medium and low-power circuits.

Sensitivity: Typical value of 185mV/A (at 5V supply voltage), with output voltage varying linearly with current for direct ADC acquisition and calculation.

Linearity error: Maximum ±1.5% (full-scale range) to ensure measurement accuracy; low temperature drift, suitable for wide-temperature environment applications.

Electrical Characteristics

Supply voltage: 4.5V ~ 5.5V (typical 5V), compatible with power systems of mainstream microcontrollers (MCUs).

Zero-current output: 2.5V (1/2 of the supply voltage) as the reference point; output is above 2.5V for positive current and below 2.5V for negative current.

Output voltage range: 0.5V ~ 4.5V (exceeding this range may enter saturation, which should be avoided), ensuring matching with ADC input ranges (usually 0~3.3V or 0~5V).

Response speed: Bandwidth of approximately 80kHz, capable of capturing fast-changing pulsed currents (e.g., motor startup, load mutation scenarios).

Isolation and Safety Features

Electrical isolation: Adopts Hall effect non-contact measurement, with an isolation voltage of 2.1kV RMS between the current path (IP+/- pins) and signal circuit (VCC, GND, OUT). It meets safety isolation requirements and protects control circuits from high-voltage interference.

Low power consumption: Typical quiescent current of 3mA, suitable for battery-powered or low-power systems.

Package and Structure

Package type: Compact TO-92-5L through-hole package with a compact pin layout, facilitating manual soldering and PCB layout.

Internal structure: Integrates a Hall sensor, signal conditioning circuit, and current conduction path (copper conductor bar). When current flows from IP+ to IP-, the magnetic field generated by the conductor bar is detected by the Hall element, amplified, and output as a corresponding voltage signal through the OUT pin.

Typical Application Scenarios

Motor control: Current monitoring and overcurrent protection for DC motors and stepper motors.

Power supply systems: Load current monitoring for switching power supplies and lithium battery chargers to prevent overload.

Battery management: Charge/discharge current detection for electric vehicle/drone batteries, estimating state of charge (SOC).

Industrial automation: Current feedback for PLC modules and frequency converters to achieve closed-loop control.

Consumer electronics: Current protection circuits for smart home devices (e.g., robot vacuums, air