Data Sheet

ManualsBrandsPololu ManualsCurrent SensorsACS709 Current Sensor Carrier -75A to 75A

ACS709

Description

The Allegro

™

ACS709 current sensor IC provides economical

and precise means for current sensing applications in industrial,

automotive, commercial, and communications systems. The

device is offered in a small footprint surface mount package

that allows easy implementation in customer applications.

The ACS709 consists of a precision linear Hall sensor integrated

circuit with a copper conduction path located near the surface

of the silicon die. Applied current flows through the copper

conduction path, and the analog output voltage from the Hall

sensor IC linearly tracks the magnetic field generated by the

applied current. The accuracy of the ACS709 is maximized

with this patented packaging configuration because the Hall

element is situated in extremely close proximity to the current

to be measured.

High level immunity to current conductor dV/dt and stray

electric fields, offered by Allegro proprietary integrated shield

technology, provides low output ripple and low offset drift in

high-side applications.

The voltage on the Overcurrent Input (VOC pin) allows

customers to define an overcurrent fault threshold for the

device. When the current flowing through the copper conduction

path (between the IP+ and IP– pins) exceeds this threshold,

ACS709A-DS, Rev. 3

Features and Benefits

▪ Industry-leading noise performance with 120 kHz

bandwidth through proprietary amplifier and filter

design techniques

▪ Integrated shield greatly reduces capacitive coupling

from current conductor to die due to high dV/dt, and

prevents offset drift in high-side applications

▪ Small footprint surface mount QSOP24 package

▪ Highisolationvoltage,suitableforline-powered

applications

▪ 1.1mΩprimaryconductorresistanceforlowpowerloss

▪ User-settable Overcurrent Fault level

▪ Overcurrent Fault signal typically responds to an

overcurrentconditionin<2μs

▪ Filter pin capacitor sets analog signal bandwidth

▪ ±2% typical output error

▪ 3 to 5.5 V, single supply operation

▪ Factory trimmed sensitivity, quiescent output voltage,

and associated temperature coefficients

▪ Chopper stabilization results in extremely stable

quiescent output voltage

▪ Ratiometric output from supply voltage

High Bandwidth, Fast Fault Response Current Sensor IC

In Thermally Enhanced Package

Continued on the next page…

Typical Application

, R

Sets resistor divider reference for V

Noise and bandwidth limiting filter capacitor

Fault delay setting capacitor, 22 nF maximum

Use of capacitor required

Use of resistor optional

Package: 24 pin QSOP (suffix LF)

Approximate Scale

IP+

IP–

FAULT_EN

VOC

VCC

FAULT

VIOUT

FILTER

VZCR

GND

ACS709

0.1 µF

330 kΩ

1 nF

IOUT

Fault_EN

Summary of content (21 pages)

PAGE 1
ACS709 High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package Features and Benefits ▪ Industry-leading noise performance with 120 kHz bandwidth through proprietary amplifier and filter design techniques ▪ Integrated shield greatly reduces capacitive coupling from current conductor to die due to high dV/dt, and prevents offset drift in high-side applications ▪ Small footprint surface mount QSOP24 package ▪ High isolation voltage, suitable for line-powered applications ▪ 1.
PAGE 2
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Description (continued) the open drain Overcurrent Fault pin will transition to a logic low state. Factory programming of the linear Hall sensor IC inside of the ACS709 results in exceptional accuracy in both analog and digital output signals. The internal resistance of the copper path used for current sensing is typically 1.1 mΩ, for low power loss.
PAGE 3
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Functional Block Diagram VCC Hall Bias FAULT_EN D Q CLK R POR POR FAULT Reset Drain – VOC + 2VREF Control Logic FAULT 3 mA Fault Comparator – Sensitivity Trim IP+ VZCR + VIOUT Signal Recovery RF(INT) Hall Amplifier IP– VOUT(Q) Trim GND FILTER Terminal List Table Number Pin-out Diagram Name Description 1 through 6 IP+ Sensed current copper conduction path pins.
PAGE 4
ACS709 High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package COMMON OPERATING CHARACTERISTICS Valid at TA = –40°C to 150°C, VCC = 5 V, unless otherwise specified Characteristic ELECTRICAL CHARACTERISTICS Supply Voltage1 Nominal Supply Voltage Supply Current Output Capacitance Load Output Resistive Load Magnetic Coupling from Device Conductor to Hall Element Internal Filter Resistance2 Symbol Min. Typ. Max. Units 3 – – 5 5.
PAGE 5
ACS709 High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package COMMON OPERATING CHARACTERISTICS (continued) Valid at TA = –40°C to 150°C, VCC = 5 V, unless otherwise specified Characteristic Symbol OVERCURRENT CHARACTERISTICS (continued) Fault Enable (FAULT_EN Pin) Delay9 tFED Overcurrent Fault Response Time tOC Overcurrent Fault Reset Delay tOCR Overcurrent Fault Reset Hold Time tOCH Overcurrent Input Pin Resistance VOLTAGE REFERENCE CHARACTERISTICS Voltage Reference
PAGE 6
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 X6BB PERFORMANCE CHARACTERISTICS, TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ. Max. Units Optimized Accuracy Range IP(OA) –6.5 – 6.5 A Linear Sensing Range IP(LIN) –15 – 15 A – 2.5 – mV Performance Characteristics at VCC = 3.3 V Noise1 VNOISE(rms) TA = 25°C, Sens = 90 mV/A, Cf = 0, CLOAD = 4.
PAGE 7
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 X20BB PERFORMANCE CHARACTERISTICS, TA Range L, valid at TA = – 40°C to 150°C, VCC = 5 V, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ. Max. Units Optimized Accuracy Range IP(OA) –20 – 20 A Linear Sensing Range IP(LIN) –37.5 – 37.5 A – 1.50 – mV Performance Characteristics at VCC = 5 V Noise1 VNOISE(rms) TA = 25°C, Sens = 56 mV/A, Cf = 0, CLOAD = 4.
PAGE 8
ACS709 High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package Thermal Characteristics Characteristic Symbol Steady State Package Thermal Resistance Transient Package Thermal Resistance Test Conditions Value Units RθJA Tested with 30 A DC current and based on ACS709 demo board in 1 cu. ft. of still air. Please refer to product FAQs page on Allegro web site for detailed information on ACS709 demo board.
PAGE 9
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Characteristic Performance ACS709 Bandwidth versus External Capacitor Value, CF Capacitor connected between FILTER pin and GND 1000 Bandwidth (kHz) 100 10 1 0.1 0.01 0.
PAGE 10
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Characteristic Performance Data Data taken using the ACS709-6BB, VCC = 3.3 V Accuracy Data Electrical Offset Voltage versus Ambient Temperature Sensitivity versus Ambient Temperature 93.0 20 92.0 Sens (mV/A) 30 VOE (mV) 10 0 -10 91.0 90.0 89.0 88.0 -20 87.0 -30 86.0 -40 –50 -25 0 25 50 75 100 125 85.
PAGE 11
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Characteristic Performance Data Data taken using the ACS709-10BB, VCC = 5 V Accuracy Data Electrical Offset Voltage versus Ambient Temperature Sensitivity versus Ambient Temperature 86.5 30 86.0 Sens (mV/A) 20 VOE (mV) 10 0 -10 -20 85.0 84.5 84.0 83.5 83.0 -30 -40 –50 85.5 82.5 -25 0 25 50 75 100 125 82.
PAGE 12
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Characteristic Performance Data Data taken using the ACS709-20BB, VCC = 5 V Accuracy Data 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35 –50 Sensitivity versus Ambient Temperature 58.0 57.5 Sens (mV/A) VOE (mV) Electrical Offset Voltage versus Ambient Temperature 57.0 56.5 56.0 55.5 -25 0 25 50 75 100 125 55.
PAGE 13
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Characteristic Performance Data Data taken using the ACS709-35BB, VCC = 5 V Accuracy Data Sensitivity versus Ambient Temperature 20 29.0 15 28.8 10 28.6 Sens (mV/A) VOE (mV) Electrical Offset Voltage versus Ambient Temperature 5 0 -5 -10 28.4 28.2 28.0 -15 27.8 -20 27.6 -25 –50 -25 0 25 50 75 100 125 27.
PAGE 14
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Setting Overcurrent Fault Switchpoint Setting 20BB and 35BB Versions The VOC needed for setting the overcurrent fault switchpoint can be calculated as follows: VOC = Sens × | IOC | , where VOC is in mV, Sens in mV/A, and IOC (overcurrent fault switchpoint) in A.
PAGE 15
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Setting 10BB and 6BB Versions The VOC needed for setting the overcurrent fault switchpoint can be calculated as follows: VOC = 1.17 × Sens × | IOC | , where VOC is in mV, Sens in mV/A, and IOC (overcurrent fault switchpoint) in A.
PAGE 16
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Functional Description Overcurrent Fault Operation The primary concern with high-speed fault detection is that noise may cause false tripping. Various applications have or need to be able to ignore certain faults that are due to switching noise or other parasitic phenomena, which are application dependant.
PAGE 17
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 6. This curve shows VCC charging external capacitor COC through the internal PMOS pull-up. The slope is determined by COC. 7. When the FAULT_EN pin is brought low, if the fault condi¯T̄ ¯ pin will stay low until tion still exists, the latched F̄¯Ā¯Ū¯L̄ the fault condition is removed, then it will start resetting. 8. At this point there is a fault condition, and the part is enabled ¯T̄ ¯ pin can charge to VCC.
PAGE 18
ACS709 High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package Definitions of Accuracy Characteristics Sensitivity (Sens). The change in device output in response to a 1 A change through the primary conductor. The sensitivity is the product of the magnetic circuit sensitivity (G / A) and the linear IC amplifier gain (mV/G). The linear IC amplifier gain is programmed at the factory to optimize the sensitivity (mV/A) for the full-scale current of the device. Noise (VNOISE).
PAGE 19
ACS709 High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package Definitions of Dynamic Response Characteristics I (%) Propagation delay (tPROP). The time required for the device output to reflect a change in the primary current signal. Propagation delay is attributed to inductive loading within the linear IC package, as well as in the inductive loop formed by the primary conductor geometry. Propagation delay can be considered as a fixed time offset and may be compensated.
PAGE 20
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Package LF, 24-pin QSOP 8º 0º 8.66 ±0.10 24 0.25 0.15 3.91 ±0.10 2.30 5.00 5.99 ±0.20 A 1 1.27 0.41 2 0.25 BSC Branded Face 24X 1.75 MAX 0.20 C 0.30 0.20 0.635 BSC 1.04 REF SEATING PLANE C 0.40 B SEATING PLANE GAUGE PLANE 0.25 MAX TLF-AAA LLLLLLLLLLL A Terminal #1 mark area All pads a minimum of 0.
PAGE 21
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package ACS709 Revision History Revision Revision Date 3 June 6, 2014 Description of Revision Added 10BB and 6BB parts Copyright ©2008-2014, Allegro MicroSystems, LLC The products described herein are protected by U.S. patents: 7,166,807; 7,425,821; 7,573,393; and 7,598,601.