ACS711

ACS711
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ACS711

Product catalog summary
Features and Benefits
  • No need for an external sense resistor; integrated solution.
  • Minimized power loss with internal conductor resistance of 0.6 mΩ (EX package) and 1.2 mΩ (LC package).
  • Cost-effective current sensing for both low- and high-side applications with output voltage proportional to AC or DC currents.
  • Full-scale sensing ranges include ±12.5 A and ±25 A for the LC package, and ±15.5 A and ±31 A for the EX package.
  • Overcurrent protection activates at 100% of full-scale current.
  • Low-noise analog signal path with a bandwidth of 100 kHz.
  • Compact SOIC8 and QFN packages with a low profile.
  • Operates on a single supply voltage ranging from 3.0 to 5.5 V.
  • Integrated electrostatic shield for stable output and factory-calibrated for precision.
  • Stable output offset voltage and zero magnetic hysteresis.
  • Ratiometric output relative to supply voltage.
Description

The Allegro™ ACS711 is engineered for precise AC or DC current sensing in applications below 100 V, such as audio and communication systems. It utilizes a linear Hall sensor circuit with a copper conduction path to generate a magnetic field, which the Hall IC senses and converts into a proportional voltage. The device is optimized for low-side current sensing and provides electrical isolation from the sensor IC leads.

Specifications
  • Supply Voltage: 3 to 5.5 V.
  • Supply Current: 4 to 5.5 mA.
  • Output Capacitance Load: up to 1 nF.
  • Primary Conductor Resistance: 0.6 mΩ (EX package), 1.2 mΩ (LC package).
  • Internal Bandwidth: 100 kHz.
  • Nonlinearity: ±1% over the full range of IP.
  • Quiescent Output Voltage: VCC / 2 at IP = 0 A.
Performance Characteristics
  • Optimized Accuracy Range: Varies by package and temperature range, e.g., ±12.5 A for LC package.
  • Sensitivity: Varies by package, e.g., 110 mV/A for LC package.
  • Noise: 11 mV without an external low pass filter on VIOUT.
  • Total Output Error: ±5% for IP = ±12.5 A, TA = –40°C to 85°C.
Thermal Characteristics
  • Package Thermal Resistance, Junction to Lead: 5 ºC/W for LC package.
  • Package Thermal Resistance, Junction to Ambient: 23 ºC/W for LC package, 24 ºC/W for EX package.
Applications

Common applications include circuit protection, current monitoring, and motor and inverter control. The device is ideal for low AC or DC working voltage applications due to its electrical isolation and compact size.

Overview

The document outlines technical specifications and performance data for the ACS711 Hall Effect Linear Current Sensor, suitable for applications requiring less than 100 V isolation. It details accuracy, sensitivity, nonlinearity, and dynamic response characteristics.

Specifications

The ACS711 sensor operates with a supply voltage (VCC) of 3.3 V. Key parameters include sensitivity, noise, linearity, symmetry, and electrical offset voltage. The sensor's output is ratiometric to the supply voltage, meaning its output and sensitivity are proportional to VCC.

Performance Data

The document includes graphs showing the relationship between various performance metrics (e.g., nonlinearity, sensitivity, symmetry, total output error) and ambient temperature. It also provides timing data, including response time, propagation delay, and rise time.

Accuracy and Error

Accuracy is defined as the maximum deviation from the ideal output, also known as total output error. The document provides formulas for calculating linearity, symmetry, and ratiometric changes in output voltage and sensitivity.

Dynamic Response

The sensor's rise time and power-on time are discussed, with rise time affecting the bandwidth of the sensor. Power-on time is the duration required for the sensor to stabilize after the supply voltage is applied.

Application Information

Recommendations for PCB layout are provided to optimize thermal and electrical performance. This includes using sufficient copper area, heavier copper, and additional board layers for conducting primary current.

Package Information

Details on the physical dimensions and layout for the LC and EX packages are included, with reference to industry standards for PCB layout and thermal management.

Revision History

The document notes a revision in July 2013, updating characteristics tables references.

Disclaimer

Allegro MicroSystems disclaims responsibility for the use of the information and advises verifying current specifications before placing orders. The products are not intended for life support systems where failure could affect safety.

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Catalog excerpts

ACS711-1

Hall Effect Linear Current Sensor with Overcurrent Fault Output for <100 V Isolation Applications Features and Benefits ▪ No external sense resistor required; single package solution ▪ Reduced Power Loss: The Allegro™ ACS711 provides economical and precise solutions for AC or DC current sensing in <100 V audio, communications systems, and white goods. The device package allows for easy implementation by the customer. Typical applications include circuit protection, current monitoring, and motor and inverter control. ▫ 0.6 mΩ internal conductor resistance on EX package ▫ 1.2 mΩ internal conductor resistance on LC package ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ Economical low- and high-side current sensing Output voltage proportional to AC or DC currents ±12.5 A and ±25 A full scale sensing ranges on LC package ±15.5 A and ±31 A full scale sensing ranges on EX package ¯ ¯¯¯ Overcurrent ¯ ¯ ¯ ¯ ¯ trips and latches at 100% of full-scale current FAULT Low-noise analog signal path 100 kHz bandwidth Small footprint, low-profile SOIC8 and QFN packages 3.0 to 5.5 V, single supply operation Integrated electrostatic shield for output stability Factory-trimmed for accuracy Extremely stable output offset voltage Zero magnetic hysteresis Ratiometric output from supply voltage 8-pin SOICN with internally fused path (LC package) The device consists of a linear Hall sensor circuit with a copper conduction path located near the surface of the die. Applied current flowing through this copper conduction path generates a magnetic field which is sensed by the integrated Hall IC and converted into a proportional voltage. Device accuracy is optimized through the close proximity of the magnetic signal to the Hall transducer. The output of the device has a positive slope proportional to the current flow from IP+ to IP– (pins 1 and 2, to pins 3 and 4). The internal resistance of this conductive path is 0.6 mΩ for the EX package, and 1.2 mΩ for the LC package, providing a non-intrusive measurement interface that saves power in applications that require energy efficiency. The ACS711 is optimized for low-side current sensing applications, although the terminals of the conductive path are electrically isolated from the sensor IC leads, providing sufficient internal creepage and clearance dimensions for a low AC or DC working voltage applications. The thickness Continued on the next page… Application 1. The ACS711 outputs an analog signal, VIOUT , that varies linearly with the ¯ L¯ ¯ bi-directional AC or DC primary current, IP , within the range specified. The ¯ ¯¯¯ ¯ pin trips FAU¯ T when IP reaches ±100% of its full-scale current. ACS711A-DS, Rev. 2

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ACS711-2

Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications Description (continued) of the copper conductor allows survival of the device at up to 5× overcurrent conditions. assembly processes. Internally, the device is Pb-free, except for flip-chip high-temperature Pb-based solder balls, currently exempt from RoHS. The device is fully calibrated prior to shipment from the factory. The ACS711 is provided in small, surface mount packages: SOIC8 and QFN12. The leadframe is plated with 100% matte tin, which is compatible with standard lead (Pb) free printed...

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ACS711-3

Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications Functional Block Diagram VCC VCC Master Current Supply Current Fault Comparator Power-on Reset Hall Current Drive Sensitivity Temperature Coefficient Trim Dynamic Offset Cancellation Signal Recovery Sensitivity Trim 0 Ampere Offset Adjust Pin-out Diagrams Terminal List Table Name Signal ground terminal Overcurrent fault; active low Terminals for current being sensed; fused internally Terminals for current being sensed; fused internally Device power supply terminal Analog output signal Allegro MicroSystems,...

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ACS711-4

Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications COMMON OPERATING CHARACTERISTICS Valid across the full range of TA for the LC package and at TA = 25°C for the EX package, VCC = 3.3 V, unless otherwise specified Characteristic Test Conditions ELECTRICAL CHARACTERISTICS Supply Voltage1 Supply Current Output Capacitance Load Output Resistive Load Primary Conductor Resistance VIOUT Rise Time Propagation Delay Time Response Time Internal IP = IPMAX, TA = 25°C, COUT = open IP = IP(max), TA = 25°C, COUT = open IP = IP(max), TA = 25°C, COUT = open Over...

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ACS711-5

Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications x12AB PERFORMANCE CHARACTERISTICS for LC package and E Temperature Range1 TA = 25°C and VCC = 3.3 V, unless otherwise specified Characteristic Optimized Accuracy Range Test Conditions Full scale of IP applied for 5 ms, TA = –40°C to 25°C TA = 25°C, no external low pass filter on VIOUT VOE(TA) Electrical Offset Voltage Full scale of IP applied for 5 ms, TA = 25°C to 85°C –12.5 Over full range of IP Characteristic Performance Data for parameter distributions over temperature. 2±3 sigma noise voltage....

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ACS711-6

Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications x25AB PERFORMANCE CHARACTERISTICS for for LC package and E Temperature Range1 TA = 25°C and VCC = 3.3 V, unless otherwise specified Characteristic Optimized Accuracy Range Test Conditions Full scale of IP applied for 5 ms, TA = –40°C to 25°C TA = 25°C, no external low pass filter on VIOUT Over full range of IP Full scale of IP applied for 5 ms, TA = –40°C to 25°C Full scale of IP applied for 5 ms, TA = 25°C to 125°C TA = 25°C, no external low pass filter on VIOUT Electrical Offset Voltage Full scale...

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ACS711-7

Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications Thermal Characteristics Characteristic Package Thermal Resistance, Junction to Lead Package Thermal Resistance, Junction to Ambient2 Symbol RθJL LC package, mounted on Allegro ASEK 711 evaluation board LC package, mounted on Allegro 85-0404 evaluation board, includes the power consumed by the board EX package, mounted on Allegro 85-0528 evaluation board, includes the power consumed by the board thermal information available on the Allegro website evaluation board has 1500 mm2 of 2 oz. copper on...

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