Document
ACS781xLR
High-Precision Linear Hall-Effect-Based Current Sensor IC with 200 µΩ Current Conductor
FEATURES AND BENEFITS
▪ Core-less, micro-sized, 100 A continuous current package ▪ Ultra-low power loss: 200 µΩ internal conductor
resistance ▪ Immunity to common-mode field interference ▪ Greatly improved total output error through digitally
programmed and compensated gain and offset over the full operating temperature range ▪ Industry-leading noise performance through proprietary amplifier and filter design techniques ▪ Integrated shield greatly reduces capacitive coupling from current conductor to die due to high dV/dt signals, and prevents offset drift in high-side, high-voltage applications ▪ Monolithic Hall IC for high reliability ▪ 3 to 3.6 V, single supply operation ▪ 120 kHz typical bandwidth ▪ 3.6 µs output rise time in response to step input current ▪ Output voltage proportional to AC or DC currents ▪ Factory-trimmed for accuracy ▪ Extremely stable quiescent output voltage ▪ AEC-Q100 automotive qualification
PACKAGE:
7-pin PSOF package (suffix LR)
DESCRIPTION
The Allegro ACS781xLR is a fully integrated current sensor linear IC in a new core-less package designed to sense AC and DC currents up to 100 A. This automotive-grade, low-profile (1.5 mm thick) sensor IC package has a very small footprint. The Hall sensor technology also incorporates common-mode field rejection to optimize performance in the presence of interfering magnetic fields generated by nearby current carrying conductors.
The device consists of a precision, low-offset linear Hall circuit with a copper conduction path located near the die. Applied current flowing through this copper conduction path generates a magnetic field which the Hall IC converts into a proportional voltage. Device accuracy is optimized through the proximity of the primary conductor to the Hall transducer and factory programming of the sensitivity and quiescent output voltage at the Allegro factory.
Chopper-stabilized signal path and digital temperature compensation technology also contribute to the stability of the device across the operating temperature range.
High-level immunity to current conductor dV/dt and stray electric fields, offered by Allegro proprietary integrated shield technology for low-output voltage ripple and low-offset drift in high-side, high-voltage applications.
The output of the device has a positive slope (>VCC / 2) when an increasing current flows through the primary copper conduction
Not to scale
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ACS781xLR 5 IP+ VOUT 3
IP 6 IP–
GND 2 1
VCC
RF CF
VOUT
CBYP 0.1 µF
3.3 V
Typical Application
Application 1: The ACS781xLR outputs an analog signal, VOUT , that varies linearly with the bidirectional AC or DC primary current, IP , within the range specified. CF is for optimal noise management, with values that depend on the application.
ACS781xLR-DS, Rev. 5 MCO-0000276
February 12, 2020
ACS781xLR
High-Precision Linear Hall-Effect-Based Current Sensor IC with 200 µΩ Current Conductor
DESCRIPTION (CONTINUED)
path (from terminal 5 to terminal 6), which is the path used for current sampling. The internal resistance of this conductive path is 200 µΩ typical, providing low power loss.
The thickness of the copper conductor allows survival of the device at high overcurrent conditions. The terminals of the conductive path are electrically isolated from the signal leads (pins 1 through
4, and 7), and allows the device to operate safely with voltages up to 100 V peak on the primary conductor.
The device is fully calibrated prior to shipment from the factory. The ACS781xLR family is lead (Pb) free. All leads are plated with 100% matte tin, and there is no Pb inside the package. The heavy gauge leadframe is made of oxygen-free copper.
SELECTION GUIDE
Part Number
Sensed Current Direction
ACS781LLRTR-050B-T ACS781LLRTR-050U-T ACS781LLRTR-100B-T ACS781LLRTR-100U-T
Bidirectional Unidirectional Bidirectional Unidirectional
ACS781KLRTR-150B-T
Bidirectional
ACS781KLRTR-150U-T
Unidirectional
Primary Sampled Current, IP (A)
±50
0 to 50
±100
0 to 100
±150 transient ±100 continuous
0 to 150 transient 0 to 100 continuous
[1] Contact Allegro for additional packing options.
Sensitivity Sens (Typ.)
(mV/A) 26.4 39.6 13.2 26.4
8.8
17.6
TOP (°C) –40 to 150 –40 to 125
Packing [1] Tape and reel
Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com
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ACS781xLR
High-Precision Linear Hall-Effect-Based Current Sensor IC with 200 µΩ Current Conductor
SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Characteristic Forward Supply Voltage Reverse Supply Voltage Forward Output Voltage Reverse Output Voltage Output Source Current Output Sink Current
Nominal Operating Ambient Temperature
Maximum Junction Storage Temperature
Symbol VCC VRCC VOUT
VRIOUT IOUT(Source) IOUT(Sink)
TOP
TJ(max) Tstg
Notes
VOUT to GND Minimum.