ACS71240
Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages
FEATURES AND BENEFITSDESCRIPTION• AEC-Q100 automotive qualified• Differential Hall sensing rejects common-mode fields• Integrated shield virtually eliminates capacitive couplingfrom current conductor to die, greatly suppressing output
noise due to high dv/dt transients• Industry-leading noise performance with greatly
improved bandwidth through proprietary amplifier andfilter design techniques• High bandwidth 120 kHz analog output for faster
response times in control applications• Patented integrated digital temperature compensation
circuitry allows for near closed-loop accuracy overtemperature in an open-loop sensor• Single supply operation with nonratiometric output at
3.3 and 5 V options• Overcurrent FAULT available between 50% and 200% IP
with 1.5 µs (typ) response time
• Nonratiometric output provides immunity to noisy supplies• Small footprint QFN-12 with wettable flank and SOIC-8
suitable for space-constrained automotive applications• 0.6 mΩ (QFN-12) or 1.2 mΩ (SOIC-8) primaryconductor resistance for low power loss and high inrush
current withstand capability• UL certified package (SOIC-8 only) for voltage isolation

The Allegro™ ACS71240 current sensor IC is an economicaland precise solution for AC or DC current sensing in industrial,
automotive, commercial, and communications applications.

PACKAGES:

The ACS71240 is provided in small, low-profile surface-mountpackage options: QFN-12 with wettable flank and SOIC-8.
Internally, the flip-chip device is considered Pb-free. However,the solder bump connections contained within the package areavailable in Pb-free or high-temperature Pb-based options. Part
numbers followed by -S are manufactured with tin-silver-based
solder bumps, making these parts Pb-free without the use of
RoHS exemptions. Part numbers without the -S are manufactured
with Pb-based solder bumps using allowed RoHS exemptions.

The device consists of a precise, low-offset linear Hall sensor
circuit with a copper conduction path located near the surfaceof the die. Applied current flowing through this copper pathgenerates a magnetic field which is sensed by the integrated Hall
IC and converted into a proportional voltage. The resistance of
the integrated conductor is far less than typical sense resistors,
which reduces power loss and improves efficiency.
Rejection of external common-mode magnetic fields isachieved through differential sensing, enabling high accuracy inmagnetically noisy environments. A precise voltage proportional
to the measured current is generated by the low-offset, chopperstabilized Hall front end.
Zero ampere output voltage and device sensitivity areprogrammed at the Allegro factory to provide a high accuracy
solution across the full automotive temperature range.
The ACS71240 includes an integrated fault comparator for
simplified overcurrent detection. The ultrafast response time
provides the system with ample time to detect and protect
against short-circuit events.

12-contact QFN with wettable flank
8-pin SOIC
3 mm × 3 mm × 0.75 mm
with internally fused path
(EXB package)(LCB package)Not to scale

VCC

SOIC-8 ONLYTÜV America
Certificate Number:
U8V 14 11 54214 032
CB 14 11 54214 031

CB Certificate Number:
US-22334-A3-UL

IP+

VCC

CBYP
0.1 μF

IP+
VIOUT
IP

ACS71240
IP–
IP–

RPU

CLOAD

FAULT
GND

Figure 1: Typical Application
ACS71240-DS, Rev. 12
MCO-0000621

September 15, 2022

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

SELECTION GUIDEPart Number [1]SupplyVoltage, VCC(V)

Optimized
Accuracy
Range, IPR (A)Sensitivity(Typ)(mV/A)

Fault Trip
Level (A)ACS71240KEXBLT-010B3

3.3

±10

132

±10

ACS71240KEXBLT-010B3-115

3.3

±10

132

±11.5

ACS71240KEXBLT-030B3

3.3

±30

44

±30

ACS71240KEXBLT-030B3-167L

3.3

±30

44

±50, latched [3]ACS71240KEXBLT-050B3

3.3

±50

26.4

±50

ACS71240KEXBLT-050B3-120

3.3

±50

26.4

±60

ACS71240KEXBLT-010B5

5

±10

200

±10

ACS71240KEXBLT-020B5

5

±20

100

±20

ACS71240KEXBLT-020B5-150L

5

±20

100

±30, latched [3]ACS71240KEXBLT-030B5

5

±30

66

±30

ACS71240KEXBLT-045B5

5

±45

44.4

±45

ACS71240KEXBLT-050B5

5

±50

40

±50

ACS71240KEXBLT-050U5

5

50

80

50

ACS71240LLCBTR-010B3

3.3

±10

132

±10

ACS71240LLCBTR-025B3

3.3

±25

55

±25

ACS71240LLCBTR-030B3

3.3

±30

44

±30

ACS71240LLCBTR-050B3

3.3

±50

26.4

±50

ACS71240LLCBTR-020U5

5

20

200

20

ACS71240LLCBTR-045B5

5

±45

44.4

±45

ACS71240LLCBTR-050B5

5

±50

40

±50

ACS71240LLCBTR-050U5

5

50

80

50

Operating Ambient
Temperature Range,
TA (°C)

Package

Packing [2]–40 to 125

12-contact QFN withwettable flank(EXB)

1500 pieces
per 7-inch reel

–40 to 150

8-pin SOIC withinternally fused path
(LCB)

3000 pieces
per 13-inch reel[1] Devices without -S have Pb-contained construction with Pb-based solder bumps. Operating performance of -S devices are identical to devices without -S. Devices with-out -S are RoHS compliant using allowed exemptions provided in Annex III and IV of Directive 2011/65/EU [Exemptions 7(a), 15, 15(a), as applicable].
[2] Contact Allegro for additional packing options.
[3] See application section for more information regarding latched fault behavior.

Continued on next page...

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

2Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

SELECTION GUIDEPart Number [1]SupplyVoltage, VCC(V)

Optimized
Accuracy
Range, IPR (A)Sensitivity(Typ)(mV/A)

Fault Trip
Level (A)ACS71240KEXBLT-010B3-S

3.3

±10

132

±10

ACS71240KEXBLT-010B3-115-S

3.3

±10

132

±11.5

ACS71240KEXBLT-020B3-S

3.3

±20

66

±20

ACS71240KEXBLT-030B3-S

3.3

±30

44

±30

ACS71240KEXBLT-030B3-167L-S

3.3

±30

44

±50, latched [3]ACS71240KEXBLT-050B3-120-S

3.3

±50

26.4

±60

ACS71240KEXBLT-010B5-S

5

±10

200

±10

ACS71240KEXBLT-020B5-S

5

±20

100

±20

ACS71240KEXBLT-030B5-S

5

±30

66

±30

ACS71240LLCBTR-010B3-S

3.3

±10

132

±10

ACS71240LLCBTR-030B3-S

3.3

±30

44

±30

ACS71240LLCBTR-050B3-S

3.3

±50

26.4

±50

ACS71240LLCBTR-045B5-S

5

±45

44.4

±45

ACS71240LLCBTR-050U5-S

5

50

80

50

Operating Ambient
Temperature Range,
TA (°C)

Package

Packing [2]–40 to 125

12-contact QFN withwettable flank(EXB)

1500 pieces
per 7-inch reel

–40 to 150

8-pin SOIC withinternally fused path
(LCB)

3000 pieces
per 13-inch reel[1] -S denotes the lead-free construction with tin-silver-based solder bumps. Advanced information. Pb-free variants are not yet released.
[2] Contact Allegro for additional packing options.

[3] See application section for more information regarding latched fault behavior.

Naming Specification
ACS71240KEXBTR - 010B3 - 115 - S
Pb-Free without RoHS Exemption
Custom Fault Level, IFAULT
115 = 115% IPR[blank] = 100% IPR
Supply Operating Level, VCC
3 = 3.3 V
5 = 5.0 V
Current Polarity
B = Bidirectional
U = Unidirectional
Optimized Accuracy Range, IPR
Packing Option
LT = 1500 pieces per 7-inch reel (QFN-12 only)
TR = 3000 pieces per 13-inch reel (SOIC-8 only)
Package Type
EXB = QFN-12 Package with Wettable Flank
LCB = SOIC-8 Package
Operating Temperature Range, TA
K = –40°C to 125°C (QFN-12 only)
L = –40°C to 150°C (SOIC-8 only)
Allegro Current Sensor 5-digit part number

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

3Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ABSOLUTE MAXIMUM RATINGS
Characteristic

SymbolNotes

RatingUnits

Supply Voltage

VCC

6

V

Reverse Supply Voltage

VCC(R)–0.5

V

Output Voltage

VIOUT

VCC + 0.7

V

Reverse Output Voltage

VIOUT(R)–0.5

V

FAULT Voltage

VFAULT

25

V

Reverse FAULT Voltage

VFAULT(R)–0.5

V

QFN-12 package

60

A

SOIC-8 package

55

A

Range K (QFN-12 package)–40 to 125°C

Range L (SOIC-8 package)–40 to 150°C

TJ(MAX)

165

°C

Tstg

–65 to 170

°C

Value

Unit

SOIC-8 package

±6.5

kV

QFN-12 package

±4.0

kV

±1

kV

Maximum Continuous Current

ICMAX

Operating Ambient Temperature Range
Maximum Junction Temperature

TA

Storage Temperature Range

TA = 25°C

ESD RATINGS
Characteristic

SymbolTest Conditions

Human Body Model

VHBM

Per JEDEC JS-001

Charged Device Model

VCDM

Per JEDEC JS-002

ISOLATION CHARACTERISTICS (for SOIC-8 package only)
Characteristic

Symbol

Notes

Value

Units

Dielectric Surge Strength Test Voltage

VSURGE

Tested ±5 pulses at 2/minute in compliance to IEC 61000-4-5
1.2 µs (rise) / 50 µs (width).

6000

V

Dielectric Strength Test Voltage

VISO

Agency type-tested for 60 seconds per UL 60950-1(edition 2); production-tested at VISO for 1 second, in
accordance with UL 60950-1 (edition 2)

2400

VRMS

Working Voltage for Basic Isolation

VWVBI

Maximum approved working voltage for basic (single)
isolation according to UL 60950-1 (edition 2)420

VPK or VDC

297

VRMS

Clearance

Dcl

Minimum distance through air from IP leads to signal leads

4.2

mm

Creepage

Dcr

Minimum distance along package body from IP leads tosignal leads

4.2

mm

Comparative Tracking Index

CTI

Material Group II

400 to 599

V

ISOLATION CHARACTERISTICS (for QFN-12 package only)
Characteristic
Working Voltage for Basic Isolation [1]SymbolVWVBI

Notes
Voltage applied between pins 1-4 and 5-12

Value

Units

100

VPK or VDC[1] Based on characterization. No agency testing was conducted.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

4Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

VCC

VIOUT

12

11

PINOUT DIAGRAMS AND TERMINAL LIST TABLES

Terminal List Table (QFN-12)

2

9

NC

IP–

3

8

NC

IP–

4

7

NC

Name

1, 2

IP+

Positive terminals for current being sensed; fused internally

3, 4

IP–

Negative terminals for current being sensed; fused internally5

GND

Signal ground terminal
Overcurrent fault; active low

6IP+

Number

5

10 NC

6

GND

1

FAULT

IP+

7, 8, 9, 10

Package EX, 12-Pin QFN
Pinout Diagram

Description

FAULT
NC

11

VIOUT

Analog output signal

12

VCC

Device power supply terminal

No connection; connect to ground for optimal ESD performance

Terminal List Table (SOIC-8)
NumberName
IP+

Positive terminals for current being sensed; fused internally

Description

IP+

1

8

VCC

1, 2

IP+

2

7

VIOUT

3, 4

IP–

Negative terminals for current being sensed; fused internally

IP–

3

6

FAULT

IP–

4

5

GND

5

GND

Signal ground terminal

6

FAULT

Overcurrent fault; active low

7

VIOUT

Analog output signal

8

VCC

Device power supply terminal

Package LC, 8-Pin SOIC
Pinout Diagram

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

5Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

Master Current
SupplyTo All Subcircuits

VCC

Power On
Reset
Temperature
Sensor

EEPROM andControl Logic

Programming
Control
FAULT
Fault Delay
Logic

Hall
Current
Drive
Sensitivity
Control

IP+
IP+

OffsetControl

Fault
Comparator

Dynamic Offset
Cancellation
VIOUT

IP–
IP–
GND

Functional Block Diagram

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

6Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

COMMON ELECTRICAL CHARACTERISTICS: Valid through the full range of TA and VCC = 5 V or 3.3 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

5 V variant

4.5

5.0

5.5

V

3.3 V variant

3.0

3.3

3.6

V

5 V variant, no load on VIOUT

–

10

12

mA

3.3 V variant, no load on VIOUT

–

7.5

12

mA

ELECTRICAL CHARACTERISTICS
Supply Voltage

VCC

Supply Current

ICC

Output Capacitive Load

CL

VIOUT to GND

–

–

4.7

nF

Output Resistive Load

RL

VIOUT to GND

10

–

–

kΩ

Primary Conductor ResistanceRIP

TA = 25°C

QFN-12 package

–

0.6

–

mΩ

SOIC-8 package

–

1.2

–

mΩ

Primary Conductor Inductance

LIP

TA = 25°C

QFN-12 package

–

1.5

–

nH

SOIC-8 package

–

2

–

nH

Primary Hall Coupling Factor

G1

TA = 25°C

QFN-12 package

–

10

–

G/A

SOIC-8 package

–

11

–

G/A

Secondary Hall Coupling Factor

G2

TA = 25°C

QFN-12 package

–

–2

–

G/A

SOIC-8 package

–

–2.8

–

G/A

Hall Plate Sensitivity Matching

Sensmatch

TA = 25°C

–

±1

–

%

Common Mode Field Rejection

CMFR

QFN-12 package

–

1.2

–

mA/G

SOIC-8 package

–

0.6

–

mA/G

Offset due to DC common field

Rise Time [2]trTA = 25°C, CL = 1 nF

–

3

4

μs

Propagation Delay [2]tpd

TA = 25°C, CL = 1 nF

–

1.6

2.2

μs

Response Time [2]tRESPONSE

TA = 25°C, CL = 1 nF

–

4

4.9

μs

Output Slew RateSR

TA = 25°C, CL = 1 nF

–

0.53

–

V/µs

Bandwidth

BW

Small signal –3 dB; CL = 1 nF

–

120

–

kHz

–

µARMS/√Hz

Noise Density

IND

Noise

IN

Nonlinearity

ELIN

Power Supply Rejection Ratio

PSRR

VCC = 5.0 V, input referred, TA = 25°C, CL = 1 nF
VCC = 3.3 V, input referred, TA = 25°C, CL = 1 nF

Power-On Time

100

µARMS/√Hz

150

VCC = 5.0 V, input referred, TA = 25°C, CL = 1 nF

–

52

–

mARMS

VCC = 3.3 V, input referred, TA = 25°C, CL = 1 nF

–

78

–

mARMS

Up to IP = 10 A

QFN-12 package

–1

–

1

%

Through full range of IP

SOIC-8 package

–1

–

1

%

VCC = VCC ±10%, TA = 25°C, DC to 1 kHz

–

40

–

dB

VCC = VCC ±10%, TA = 25°C, 1 kHz to 20 kHz

–

30

–

dB

VCC = VCC ±10%, TA = 25°C, 20 kHz to 60 kHz
Output Saturation Voltage [3]

–

–

20

–

dB

VSAT_H

RL = 10 kΩ

VCC – 0.3––

V

VSAT_LRL = 10 kΩ

–

–

0.3

V

tPO

TA = 25°C

–

80

–

μs

Shorted Output-to-Ground Current

ISC(GND)

TA = 25°C

–

30

–

mA

Shorted Output-to-VCC Current

ISC(VCC)TA = 25°C

–

1.8

–

mA

Continued on next page...

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

7Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

COMMON ELECTRICAL CHARACTERISTICS (continued): Valid through the full range of TA and VCC, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

3

12

–

%

10

–

500

kΩ

–

–

0.3

V

–

1.5

2.5

µs

IFAULT, TA = 25°C

–10

±3.5

10

%

TA = –40°C or TA(MAX)

–10

±5

10

%

FAULT CHARACTERISTICS
FAULT Current Hysteresis [4]IF(HYS)

FAULT Output Pullup Resistor

RPU

FAULT Output Voltage

VOL

Percent of IPR(MAX)RPU = 10 kΩ, during fault condition
Time from |IP| rising above |IFAULT| until VFAULT <FAULT Response Time [5]tFAULT

VOL(MAX). 100 pF from FAULT to GND.
Input current step 20% above IFAULT with rise time
≤ 1 µs.

FAULT Error

EF[1] Typical values with ± are 3 sigma values.

[2] Guaranteed by design. Limit calculated using 6 sigma. Not tested in production.
[3] The sensor will continue to respond to current beyond the range of I

P until the high or low saturation voltage; however, the nonlinearity in this region will be worse than
through the rest of the measurement range. The extended current sensing range, IP(EXT), can be calculated using the following equation:
IP(EXT) [A] = (VSAT_H [V] – VIOUT(Q) [V]) × 1000 / Sens [mV/A].
[4] Tested on all devices using trim settings set to ACS71240-10B.
[5] Not tested in production.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

8Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240KEXBLT-010B3 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 3.3 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–10

–

10

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

132

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

1.65

–

V

IP = 10 A, TA = 25°C to 125°C

–2.5

±1.2

2.5

%

IP = 10 A, TA = –40°C to 25°C

–6

±2.5

6

%

IP = 10 A, TA = 25°C to 125°C

–2

±1.0

2

%

IP = 10 A, TA = –40°C to 25°C

–5.5

±2.2

5.5

%

IP = 0 A, TA = 25°C to 125°C

–15

±6.3

15

mV

IP = 0 A, TA = –40°C to 25°C

–30

±8.6

30

mV

IP = 10 A, TA = 25°C to 125°C

–5.7

±1.8

5.7

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.5

6

%

IP = 10 A, TA = 25°C to 125°C

–5.1

±1.2

5.1

%

IP = 10 A, TA = –40°C to 25°C

–5.6

±1.2

5.6

%

IP = 0 A, TA = 25°C to 125°C

–28

±4.5

28

mV

IP = 0 A, TA = –40°C to 25°C

–30

±4.3

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

ACCURACY PERFORMANCE INCLUDING LIFETIME DRIFT [4]Total Output Error Including
Lifetime Drift [5]ETOT_drift

Sensitivity Error Including
Lifetime Drift [6]ESENS_drift

Offset Voltage Error Including
Lifetime Drift [7]VOE_drift

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values, except for lifetime drift, which are the average value including drift (from the worst-case stress) after AEC-Q100 qualification.

[2] Percentage of I .
P[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

[4] Lifetime drift characteristics are based on AEC-Q100 qualification results.

[5] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 6.1%.
[6] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 4%.

[7] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 22 mV.

ACS71240KEXBLT-010B3-115 Variant
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–

±1.15 × IPR–

A

NON-STANDARD FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

9Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240KEXBLT-030B3 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 3.3 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–30

–

30

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

44

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

1.65

–

V

IP = 10 A, TA = 25°C to 125°C

–2.5

±1.2

2.5

%

IP = 10 A, TA = –40°C to 25°C

–6

±2.5

6

%

IP = 10 A, TA = 25°C to 125°C

–2

±1.5

2

%

IP = 10 A, TA = –40°C to 25°C

–5.5

±2.4

5.5

%

IP = 0 A, TA = 25°C to 125°C

–15

±3.8

15

mV

IP = 0 A, TA = –40°C to 25°C

–30

±7.1

30

mV

IP = 10 A, TA = 25°C to 125°C

–5.7

±1.8

5.7

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.5

6

%

IP = 10 A, TA = 25°C to 125°C

–5.1

±1.2

5.1

%

IP = 10 A, TA = –40°C to 25°C

–5.6

±1.2

5.6

%

IP = 0 A, TA = 25°C to 125°C

–28

±4.5

28

mV

IP = 0 A, TA = –40°C to 25°C

–30

±4.3

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

ACCURACY PERFORMANCE INCLUDING LIFETIME DRIFT [4]Total Output Error Including
Lifetime Drift [5]ETOT_drift

Sensitivity Error Including
Lifetime Drift [6]ESENS_drift

Offset Voltage Error Including
Lifetime Drift [7]VOE_drift

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values, except for lifetime drift, which are the average value including drift (from the worst-case stress) after AEC-Q100 qualification.

[2] Percentage of I .
P[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

[4] Lifetime drift characteristics are based on AEC-Q100 qualification results.

[5] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 6.1%.
[6] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 4%.

[7] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 22 mV.

ACS71240KEXBLT-030B3-167L Variant
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–

±1.67 × IPR–

A

NON-STANDARD FAULT CHARACTERISTICS
FAULT Operating Point
Fault Latch

IFAULT–

Enabled–[1] Typical values are mean ± 3 sigma values

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

10Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240KEXBLT-050B3 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 3.3 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–50

–

50

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

26.4

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

1.65

–

V

IP = 10 A, TA = 25°C to 125°C

–2.5

±1.5

2.5

%

IP = 10 A, TA = –40°C to 25°C

–6

±2.6

6

%

IP = 10 A, TA = 25°C to 125°C

–2

±1.1

2

%

IP = 10 A, TA = –40°C to 25°C

–5.5

±1.7

5.5

%

IP = 0 A, TA = 25°C to 125°C

–15

±3

15

mV

IP = 0 A, TA = –40°C to 25°C

–30

±10

30

mV

IP = 10 A, TA = 25°C to 125°C

–5.7

±1.8

5.7

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.5

6

%

IP = 10 A, TA = 25°C to 125°C

–5.1

±1.2

5.1

%

IP = 10 A, TA = –40°C to 25°C

–5.6

±1.2

5.6

%

IP = 0 A, TA = 25°C to 125°C

–28

±4.5

28

mV

IP = 0 A, TA = –40°C to 25°C

–30

±4.3

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

ACCURACY PERFORMANCE INCLUDING LIFETIME DRIFT [4]Total Output Error Including
Lifetime Drift [5]ETOT_drift

Sensitivity Error Including
Lifetime Drift [6]ESENS_drift

Offset Voltage Error Including
Lifetime Drift [7]VOE_drift

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values, except for lifetime drift, which are the average value including drift (from the worst-case stress) after AEC-Q100 qualification.

[2] Percentage of I .
P[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

[4] Lifetime drift characteristics are based on AEC-Q100 qualification results.

[5] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 6.1%.
[6] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 4%.

[7] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 22 mV.

ACS71240KEXBLT-050B3-120 Variant
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–

±1.2 × IPR–

A

NON-STANDARD FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

11Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240KEXBLT-010B5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–10

–

10

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

200

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

2.5

–

V

IP = 10 A, TA = 25°C to 125°C

–2.5

±1.2

2.5

%

IP = 10 A, TA = –40°C to 25°C

–6

±2.4

6

%

IP = 10 A, TA = 25°C to 125°C

–2

±0.8

2

%

IP = 10 A, TA = –40°C to 25°C

–5.5

±2.5

5.5

%

IP = 0 A, TA = 25°C to 125°C

–15

±4.4

15

mV

IP = 0 A, TA = –40°C to 25°C

–30

±9.6

30

mV

IP = 10 A, TA = 25°C to 125°C

–5.7

±1.8

5.7

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.5

6

%

IP = 10 A, TA = 25°C to 125°C

–5.1

±1.2

5.1

%

IP = 10 A, TA = –40°C to 25°C

–5.6

±1.2

5.6

%

IP = 0 A, TA = 25°C to 125°C

–28

±4.5

28

mV

IP = 0 A, TA = –40°C to 25°C

–30

±4.3

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Offset Voltage Error

ESENS
VOE

ACCURACY PERFORMANCE INCLUDING LIFETIME DRIFT [4]Total Output Error Including
Lifetime Drift [5]ETOT_drift

Sensitivity Error Including
Lifetime Drift [6]ESENS_drift

Offset Voltage Error Including
Lifetime Drift [7]VOE_drift

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values, except for lifetime drift, which are the average value including drift (from the worst-case stress) after AEC-Q100 qualification.

[2] Percentage of I .
P[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

[4] Lifetime drift characteristics are based on AEC-Q100 qualification results.

[5] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 6.1%.
[6] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 4%.

[7] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 22 mV.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

12Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240KEXBLT-020B5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–20

–

20

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

100

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

2.5

–

V

IP = 10 A, TA = 25°C to 125°C

–2.5

±1.1

2.5

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.7

6

%

IP = 10 A, TA = 25°C to 125°C

–2

±1.1

2

%

IP = 10 A, TA = –40°C to 25°C

–5.5

±2.0

5.5

%

IP = 0 A, TA = 25°C to 125°C

–10

±3.8

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±11

30

mV

IP = 10 A, TA = 25°C to 125°C

–5.7

±1.8

5.7

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.5

6

%

IP = 10 A, TA = 25°C to 125°C

–5.1

±1.2

5.1

%

IP = 10 A, TA = –40°C to 25°C

–5.6

±1.2

5.6

%

IP = 0 A, TA = 25°C to 125°C

–28

±4.5

28

mV

IP = 0 A, TA = –40°C to 25°C

–30

±4.3

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Offset Voltage Error

ESENS
VOE

ACCURACY PERFORMANCE INCLUDING LIFETIME DRIFT [4]Total Output Error Including
Lifetime Drift [5]ETOT_drift

Sensitivity Error Including
Lifetime Drift [6]ESENS_drift

Offset Voltage Error Including
Lifetime Drift [7]VOE_drift

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values, except for lifetime drift, which are the average value including drift (from the worst-case stress) after AEC-Q100 qualification.

[2] Percentage of I .
P[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

[4] Lifetime drift characteristics are based on AEC-Q100 qualification results.

[5] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 6.1%.
[6] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 4%.

[7] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 22 mV.

ACS71240KEXBLT-020B5-150L Variant
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–

±1.5 × IPR–

A

NON-STANDARD FAULT CHARACTERISTICS
FAULT Operating Point
Fault Latch

IFAULT–

Enabled–[1] Typical values are mean ± 3 sigma values

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

13

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240KEXBLT-030B5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–30

–

30

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

66

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

2.5

–

V

IP = 10 A, TA = 25°C to 125°C

–2.5

±1.2

2.5

%

IP = 10 A, TA = –40°C to 25°C

–6

±2.2

6

%

IP = 10 A, TA = 25°C to 125°C

–2

±0.9

2

%

IP = 10 A, TA = –40°C to 25°C

–5.5

±1.5

5.5

%

IP = 0 A, TA = 25°C to 125°C

–15

±3.7

15

mV

IP = 0 A, TA = –40°C to 25°C

–30

±7.1

30

mV

IP = 10 A, TA = 25°C to 125°C

–5.7

±1.8

5.7

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.5

6

%

IP = 10 A, TA = 25°C to 125°C

–5.1

±1.2

5.1

%

IP = 10 A, TA = –40°C to 25°C

–5.6

±1.2

5.6

%

IP = 0 A, TA = 25°C to 125°C

–28

±4.5

28

mV

IP = 0 A, TA = –40°C to 25°C

–30

±4.3

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

ACCURACY PERFORMANCE INCLUDING LIFETIME DRIFT [4]Total Output Error Including
Lifetime Drift [5]ETOT_drift

Sensitivity Error Including
Lifetime Drift [6]ESENS_drift

Offset Voltage Error Including
Lifetime Drift [7]VOE_drift

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values, except for lifetime drift, which are the average value including drift (from the worst-case stress) after AEC-Q100 qualification.

[2] Percentage of I .
P[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

[4] Lifetime drift characteristics are based on AEC-Q100 qualification results.

[5] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 6.1%.
[6] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 4%.

[7] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 22 mV.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

14

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240KEXBLT-045B5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–45

–

45

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

44.4

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

2.5

–

V

IP = 10 A, TA = 25°C to 125°C

–2.5

±1.5

2.5

%

IP = 10 A, TA = –40°C to 25°C

–6

±2.5

6

%

IP = 10 A, TA = 25°C to 125°C

–2

±1.2

2

%

IP = 10 A, TA = –40°C to 25°C

–5.5

±1.3

5.5

%

IP = 0 A, TA = 25°C to 125°C

–15

±4

15

mV

IP = 0 A, TA = –40°C to 25°C

–30

±10

30

mV

IP = 10 A, TA = 25°C to 125°C

–5.7

±1.8

5.7

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.5

6

%

IP = 10 A, TA = 25°C to 125°C

–5.1

±1.2

5.1

%

IP = 10 A, TA = –40°C to 25°C

–5.6

±1.2

5.6

%

IP = 0 A, TA = 25°C to 125°C

–28

±4.5

28

mV

IP = 0 A, TA = –40°C to 25°C

–30

±4.3

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

ACCURACY PERFORMANCE INCLUDING LIFETIME DRIFT [4]Total Output Error Including
Lifetime Drift [5]ETOT_drift

Sensitivity Error Including
Lifetime Drift [6]ESENS_drift

Offset Voltage Error Including
Lifetime Drift [7]VOE_drift

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values, except for lifetime drift, which are the average value including drift (from the worst-case stress) after AEC-Q100 qualification.

[2] Percentage of I .
P[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

[4] Lifetime drift characteristics are based on AEC-Q100 qualification results.

[5] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 6.1%.
[6] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 4%.

[7] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 22 mV.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

15

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240KEXBLT-050B5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–50

–

50

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

40

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

2.5

–

V

IP = 10 A, TA = 25°C to 125°C

–2.5

±1.4

2.5

%

IP = 10 A, TA = –40°C to 25°C

–6

±2.6

6

%

IP = 10 A, TA = 25°C to 125°C

–2

±1.1

2

%

IP = 10 A, TA = –40°C to 25°C

–5.5

±1.7

5.5

%

IP = 0 A, TA = 25°C to 125°C

–15

±3

15

mV

IP = 0 A, TA = –40°C to 25°C

–30

±8

30

mV

IP = 10 A, TA = 25°C to 125°C

–5.7

±1.8

5.7

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.5

6

%

IP = 10 A, TA = 25°C to 125°C

–5.1

±1.2

5.1

%

IP = 10 A, TA = –40°C to 25°C

–5.6

±1.2

5.6

%

IP = 0 A, TA = 25°C to 125°C

–28

±4.5

28

mV

IP = 0 A, TA = –40°C to 25°C

–30

±4.3

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

ACCURACY PERFORMANCE INCLUDING LIFETIME DRIFT [4]Total Output Error Including
Lifetime Drift [5]ETOT_drift

Sensitivity Error Including
Lifetime Drift [6]ESENS_drift

Offset Voltage Error Including
Lifetime Drift [7]VOE_drift

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values, except for lifetime drift, which are the average value including drift (from the worst-case stress) after AEC-Q100 qualification.

[2] Percentage of I .
P[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

[4] Lifetime drift characteristics are based on AEC-Q100 qualification results.

[5] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 6.1%.
[6] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 4%.

[7] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 22 mV.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

16

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240KEXBLT-050U5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

0

–

50

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

80

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Unidirectional, IP = 0 A

–

0.5

–

V

IP = 10 A, TA = 25°C to 125°C

–2.5

±1.2

2.5

%

IP = 10 A, TA = –40°C to 25°C

–6

±3.6

6

%

IP = 10 A, TA = 25°C to 125°C

–2

±0.9

2

%

IP = 10 A, TA = –40°C to 25°C

–5.5

±3.3

5.5

%

IP = 0 A, TA = 25°C to 125°C

–10

±4.6

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±6.3

30

mV

IP = 10 A, TA = 25°C to 125°C

–5.7

±1.8

5.7

%

IP = 10 A, TA = –40°C to 25°C

–6

±1.5

6

%

IP = 10 A, TA = 25°C to 125°C

–5.1

±1.2

5.1

%

IP = 10 A, TA = –40°C to 25°C

–5.6

±1.2

5.6

%

IP = 0 A, TA = 25°C to 125°C

–28

±4.5

28

mV

IP = 0 A, TA = –40°C to 25°C

–30

±4.3

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

ACCURACY PERFORMANCE INCLUDING LIFETIME DRIFT [4]Total Output Error Including
Lifetime Drift [5]ETOT_drift

Sensitivity Error Including
Lifetime Drift [6]ESENS_drift

Offset Voltage Error Including
Lifetime Drift [7]VOE_drift

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values, except for lifetime drift, which are the average value including drift (from the worst-case stress) after AEC-Q100 qualification.

[2] Percentage of I .
P[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

[4] Lifetime drift characteristics are based on AEC-Q100 qualification results.

[5] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 6.1%.
[6] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 4%.

[7] All devices stayed within min/max limits throughout AEC-Q100 qualification. The worst drift observed was 22 mV.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

17Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240LLCBTR-010B3 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 3.3 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–10

–

10

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

132

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

1.65

–

V

IP = IPR(max), TA = 25°C to 150°C

–2

±1

2

%

IP = IPR(max), TA = –40°C to 25°C

–6

±2.4

6

%

IP = IPR(max), TA = 25°C to 150°C

–1.5

±0.8

1.5

%

IP = IPR(max), TA = –40°C to 25°C

–5.5

±2.3

5.5

%

IP = 0 A, TA = 25°C to 150°C

–10

±6.7

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±10

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values. Limits include lifetime as tested during AEC-Q100 qualification.

[2] Percentage of I , with I = I
PP
PR(max).
[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

ACS71240LLCBTR-025B3 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 3.3 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

–25

–

25

A

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

55

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

1.65

–

V

IP = IPR(max), TA = 25°C to 150°C

–2

±1

2

%

IP = IPR(max), TA = –40°C to 25°C

–6

±1.7

6

%

IP = IPR(max), TA = 25°C to 150°C

–1.9

±0.9

1.9

%

IP = IPR(max), TA = –40°C to 25°C

–5.5

±1.4

5.5

%

IP = 0 A, TA = 25°C to 150°C

–10

±7

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±11

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values. Limits include lifetime as tested during AEC-Q100 qualification.

[2] Percentage of I , with I = I
PP
PR(max).
[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

18

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240LLCBTR-030B3 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 3.3 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–30

–

30

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

44

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

1.65

–

V

IP = IPR(max), TA = 25°C to 150°C

–2

±0.6

2

%

IP = IPR(max), TA = –40°C to 25°C

–6

±1.4

6

%

IP = IPR(max), TA = 25°C to 150°C

–1.9

±0.5

1.9

%

IP = IPR(max), TA = –40°C to 25°C

–5.5

±1.1

5.5

%

IP = 0 A, TA = 25°C to 150°C

–10

±7.2

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±9.5

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values. Limits include lifetime as tested during AEC-Q100 qualification.

[2] Percentage of I , with I = I
PP
PR(max).
[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

ACS71240LLCBTR-050B3 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 3.3 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

–50

–

50

A

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

26.4

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

1.65

–

V

IP = IPR(max), TA = 25°C to 150°C

–2

±0.9

2

%

IP = IPR(max), TA = –40°C to 25°C

–6

±4.3

6

%

IP = IPR(max), TA = 25°C to 150°C

–1.5

±0.8

1.5

%

IP = IPR(max), TA = –40°C to 25°C

–5.5

±4.2

5.5

%

IP = 0 A, TA = 25°C to 150°C

–10

±7.5

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±10

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values. Limits include lifetime as tested during AEC-Q100 qualification.

[2] Percentage of I , with I = I
PP
PR(max).
[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

19

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240LLCBTR-020U5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

0

–

20

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

200

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Unidirectional, IP = 0 A

–

0.5

–

V

IP = IPR(max), TA = 25°C to 150°C

–2

±1

2

%

IP = IPR(max), TA = –40°C to 25°C

–6

±2.2

6

%

IP = IPR(max), TA = 25°C to 150°C

–1.9

±1

1.9

%

IP = IPR(max), TA = –40°C to 25°C

–5.5

±1.9

5.5

%

IP = 0 A, TA = 25°C to 150°C

–10

±7.1

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±23

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values. Limits include lifetime as tested during AEC-Q100 qualification.

[2] Percentage of I , with I = I
PP
PR(max).
[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

ACS71240LLCBTR-045B5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–45

–

45

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

44.4

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

2.5

–

V

IP = IPR(max), TA = 25°C to 150°C

–2

±0.7

2

%

IP = IPR(max), TA = –40°C to 25°C

–6

±1.4

6

%

IP = IPR(max), TA = 25°C to 150°C

–1.9

±0.6

1.9

%

IP = IPR(max), TA = –40°C to 25°C

–5.5

±1.4

5.5

%

IP = 0 A, TA = 25°C to 150°C

–10

±6.9

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±7.2

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values. Limits include lifetime as tested during AEC-Q100 qualification.

[2] Percentage of I , with I = I
PP
PR(max).
[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

20

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

ACS71240LLCBTR-050B5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

–50

–

50

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

40

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Bidirectional, IP = 0 A

–

2.5

–

V

IP = IPR(max), TA = 25°C to 150°C

–2

±1.1

2

%

IP = IPR(max), TA = –40°C to 25°C

–6

±4

6

%

IP = IPR(max), TA = 25°C to 150°C

–1.9

±1

1.9

%

IP = IPR(max), TA = –40°C to 25°C

–5.5

±4

5.5

%

IP = 0 A, TA = 25°C to 150°C

–10

±7.7

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±7.5

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values. Limits include lifetime as tested during AEC-Q100 qualification.

[2] Percentage of I , with I = I
PP
PR(max).
[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

ACS71240LLCBTR-050U5 PERFORMANCE CHARACTERISTICS: Over full range of TA, VCC = 5.0 V, unless otherwise specified
Characteristic

SymbolTest Conditions

Min.

Typ. [1]

Max.

Unit

0

–

50

A

NOMINAL PERFORMANCE
Optimized Sensing Range

IPR

Sensitivity

Sens

IPR(min) < IP < IPR(max)

–

80

–

mV/A

Zero-Current Output Voltage

VIOUT(Q)

Unidirectional, IP = 0 A

–

0.5

–

V

IP = IPR(max), TA = 25°C to 150°C

–2

±1.1

2

%

IP = IPR(max), TA = –40°C to 25°C

–6

±3.8

6

%

IP = IPR(max), TA = 25°C to 150°C

–1.9

±1.1

1.9

%

IP = IPR(max), TA = –40°C to 25°C

–5.5

±3.8

5.5

%

IP = 0 A, TA = 25°C to 150°C

–10

±4

10

mV

IP = 0 A, TA = –40°C to 25°C

–30

±5.5

30

mV

–

±1 × IPR–A

ACCURACY PERFORMANCE
Total Output Error [2]ETOT

TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 × VOE / (Sens × IP)
Sensitivity Error
Voltage Offset Error

ESENS
VOE

FAULT CHARACTERISTICS
FAULT Operating PointIFAULT[1] Typical values are mean ± 3 sigma values. Limits include lifetime as tested during AEC-Q100 qualification.

[2] Percentage of I , with I = I
PP
PR(max).
[3] A single device will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output

error specification.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

21

ACS71240

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

CHARACTERISTIC PERFORMANCE
ACS71240 TYPICAL FREQUENCY RESPONSE-3dB ≈ 120 kHz

For information regarding bandwidth characterization methods used for the ACS71240, see the “Characterizing System Bandwidth”
application note (https://allegromicro.com/en/insights-and-innovations/technical-documents/hall-effect-sensor-ic-publications/aneffective-method-for-characterizing-system-bandwidth-an296169) on the Allegro website.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

22

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240RESPONSE CHARACTERISTICS DEFINITIONS AND PERFORMANCE DATA
Response Time (tRESPONSE)

Rise Time (tr)The time interval between a) when the sensed input current
reaches 90% of its final value, and b) when the sensor output
reaches 90% of its full-scale value.

The time interval between a) when the sensor reaches 10% of
its full-scale value, and b) when it reaches 90% of its full-scalevalue.

The time interval between a) when the sensed input current
reaches 20% of its full-scale value, and b) when the sensor output
reaches 20% of its full-scale value.

The rate of change [V/µs] in the output voltage from a) when thesensor reaches 10% of its full-scale value, and b) when it reaches
90% of its full-scale value.

Propagation Delay (tpd)

Output Slew Rate (SR)Response Time, Propagation Delay, Rise Time, and Output Slew Rate
Applied current step with 10%-90% rise time = 1 μs
Test Conditions: TA = 25°C, CBYPASS = 0.1 µF, CL = 1 nF

tRESPONSE

SR [V/μs]tpd

trAllegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

23

ACS71240

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

POWER ON FUNCTIONAL DESCRIPTION AND PERFORMANCE DATAPower-On Time (tPO)Power-On Profile

When the supply is ramped to its operating voltage, the device
requires a finite amount of time to power its internal components before responding to an input magnetic field. Power-On
Time (tPO) is defined as the time interval between a) the power
supply has reached its minimum specified operating voltage(VCC(min)), and b) when the sensor output has settled within±10% of its steady-state value under an applied magnetic field.

After applying power, the part remains off in a known, highimpedance state referred to as Power-on Reset, or POR. The
device stays in this state until the voltage reaches a point at which
the device will remain powered. The power-on profile below
illustrates the intended power on/off. A pull-down resistor wasused on the output of the tested device.

Power-On Time (tPO)
Test Conditions: TA = 25°C, CBYPASS = 0.1 µF, RPD = 10 kΩ,
1V Output Swing

Power-On Profile
Supply voltage ramp rate = 1V/ms
Test Conditions: TA = 25°C, CBYPASS = 0.1 µF, RPD = 10 kΩ

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

24

ACS71240

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

DEFINITIONS OF ACCURACY CHARACTERISTICS
Sensitivity (Sens). The change in sensor IC output in response toa 1 A change through the primary conductor. The sensitivity is the
product of the magnetic circuit sensitivity (G / A) (1 G = 0.1 mT)
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.
Nonlinearity (ELIN). The nonlinearity is a measure of how linear
the output of the sensor IC is over the full current measurement
range. The nonlinearity is calculated as:
VIOUT(IPR(max)) – VIOUT(Q)ELIN = 1–• 100(%)
2 • VIOUT(IPR(max)/2) – VIOUT(Q)

Increasing
VIOUT (V)

Accuracy at
25°C Only
IPR(min)–IP (A)

Full Scale IP

IPR(max)

0A

Accuracy at
25°C Only

Decreasing
VIOUT (V)

Accuracy AcrossTemperature

Figure 2: Output Voltage versus Sensed Current+ETOT

Across Temperature
25°C Only

VIOUT_ideal(IP) – VIOUT (IP)
• 100 (%)
Sensideal(IP) • IP

The Total Output Error incorporates all sources of error and is afunction of IP. At relatively high currents, ETOT will be mostly
due to sensitivity error, and at relatively low currents, ETOT will
be mostly due to Offset Voltage (VOE). In fact, at IP = 0, ETOT
approaches infinity due to the offset. This is illustrated in Figure
2 and Figure 3. Figure 2 shows a distribution of output voltages
versus IP at 25°C and across temperature. Figure 3 shows the corresponding ETOT versus IP .

+IP (A)

VIOUT(Q)

Total Output Error (ETOT). The difference between the current measurement from the sensor IC and the actual current (IP),relative to the actual current. This is equivalent to the difference
between the ideal output voltage and the actual output voltage,
divided by the ideal sensitivity, relative to the current flowing
through the primary conduction path:
ETOT (IP) =Accuracy at
25°C Only
Ideal VIOUT

Accuracy AcrossTemperature

Zero-Current Output Voltage (VIOUT(Q)). The output of thesensor when the primary current is zero. For unipolar devices
this value will be 10% of operating voltage, 0.5 V and 0.33 V for
5 V and 3.3 V respectively. For bidirectional devices, the output
will be 50% of the operating voltage, 2.5 V and 1.65 V for 5 V
and 3.3 V devices respectively. Since the ACS71240 is a nonratiometric part, these values will be stable over VCC variations.
Variation in VIOUT(Q) can be attributed to the resolution of theAllegro linear IC quiescent voltage trim and thermal drift.
Offset Voltage (VOE). The deviation of the device output from its
ideal quiescent value due to nonmagnetic causes. To convert thisvoltage to amperes, divide by the device sensitivity, Sens.

Accuracy AcrossTemperature

–IP

+IP

–ETOT

Figure 3: Total Output Error versus Sensed Current

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

25

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

Power Supply Rejection Ratio (PSRR). The ratio of the change
on VIOUT to a change in VCC in dB.
PSRR = 20 log10

(|

ΔVCC
ΔVIOUT|)

FAULT Error (EF). The difference between the current at which
the FAULT pin trips (IFAULT), relative to the ideal fault current(IFAULT_ideal). This is equivalent to the difference between theideal fault current and the actual fault current divided by the ideal
current, and is defined as:

EF =IFAULT – IFAULT_ideal
× 100 (%)
IFAULT_ideal

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

26

ACS71240

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

Fault Behavior
The ACS71240 is available with both a latched and unlatched
FAULT pin output. Unless otherwise stated, the default operationis unlatched.

Unlatched Fault Behavior
In the event that the FAULT pin is unlatched, the FAULT output
will only assert while an overcurrent condition is present. Whenan overcurrent condition occurs, the FAULT pin will be pulled
low within FAULT response time, tFAULT. When the overcurrent
condition is removed and IFAULT falls below the overcurrent trip
point minus the hysteresis (IF(HYS)), another tFAULT will delay therelease of the line, after which the FAULT line will return to VCC
with a time constant based on the pull-up resistor and line capacitance (refer to Figure 4).

Latched Fault Behavior

I PR
I F (HY S )tFAUL TtFAUL T

Figure 4: Fault trip with FAULT response time
FAULT

< tCLKtMASK
LatchedUnlatchedtime

Fault Filtering

In latched mode, there is an additional delay of 1 clock cycle(tCLK < 150 ns) after the overcurrent event occurs. The fault
behavior for latched and unlatched modes are shown in Figure 5
and Figure 6.

I FAUL T -I F(HYS)V FAUL T

In the event that the fault pin is latched, the FAULT output willassert when an overcurrent condition is present. The FAULT
pin will remain latched even after the overcurrent condition has
subsided. The FAULT pin will remain asserted until the device ispower-cycled.
To prevent nuisance tripping while in latched mode, theACS71240 is available with a variety of minimum fault times,
which are the minimum period a fault event must be present
before the FAULT pin will latch. This minimum period, tMASK,
can be 0 µs, 0.5 µs, or 1 µs; the default tMASK is 0 µs.

I FAUL T

Figure 5: Fault event longer than tMASK

FAULT< tCLK

LatchedtMASK

Unlatched

time

Figure 6: Fault event shorter than tMASK

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

27

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240APPLICATION INFORMATION
Thermal Rise vs. Primary Current
Self-heating due to the flow of current should be considered during the design of any current sensing system. The sensor, printed
circuit board (PCB), and contacts to the PCB will generate heat as
current moves through the system.
The thermal response is highly dependent on PCB layout, copper
thickness, cooling techniques, and the profile of the injected current.
The current profile includes peak current, current “on-time”, andduty cycle. While the data presented in this section was collectedwith direct current (DC), these numbers may be used to approximate
thermal response for both AC signals and current pulses.
The plots in Figure 7 and Figure 9 show the measured rise in steadystate die temperature of the ACS71240 in the LC package and EX
package, respectively, versus continuous current at an ambient
temperature, TA, of 25 °C. The thermal offset curves may be directly
applied to other values of TA. Figure 8 and Figure 10 show the maximum continuous current at a given TA. Surges beyond the maximum
current listed in Figure 8 and Figure 10 are allowed given the maximum junction temperature, TJ(MAX) (165℃), is not exceeded.

Figure 9: Self Heating in the EX Package
Due to Current Flow

Figure 10: Maximum Continuous Current
in the EX package at a Given TA

Figure 7: Self Heating in the LC Package
Due to Current Flow

The thermal capacity of the ACS71240 should be verified by theend user in the application’s specific conditions. The maximum
junction temperature, TJ(MAX) (165℃), should not be exceeded.
Further information on this application testing is available in
the DC and Transient Current Capability application note on the
Allegro website.

ASEK71240 Evaluation Board Layout
Thermal data shown in Figure 7 and Figure 8 was collected using theASEK71240 Evaluation Board (TED-0002524). This board includes
1500 mm2 of 4 oz. copper (0.1388 mm) connected to pins 1 and 2,
and to pins 3 and 4, with thermal vias connecting the layers. Top andbottom layers of the PCB are shown in Figure 11.

Figure 8: Maximum Continuous Current
in the LC package at a Given TA

Thermal data shown in Figure 9 and Figure 10 was collected using
the ASEK71240 Evaluation Board (TED-0002302). This board
includes 250 mm2 of 2 oz. copper (0.0694 mm) connected to pins 1
and 2, and to pins 3 and 4, with thermal vias connecting the layers.
Top and bottom layers of the PCB are shown in Figure 12.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

28

ACS71240

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

Figure 11: Top and Bottom Layers for
ASEK71240 Evaluation Board (TED-0002524)

Figure 12: Top and Bottom Layers for
ASEK71240 Evaluation Board (TED-0002302)
Gerber files for the ASEK71240 evaluation board are available
for download from our website. See the technical documents section of the ACS71240 device webpage.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

29

ACS71240

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

Common-Mode Field Rejection
The ACS71240 features two Hall-effect sensors used differentially in order to eliminate stray field. The two sensors are placedon opposite sides of the current loop. This allows the common
magnetic field to be determined and removed before the signal
is sent to the end user. Despite this common field rejection, it isalways best practice to reduce the amount of stray fields aroundthe current sensor as much as possible. See the Allegro Applications note on reducing common mode field for more details.

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

30Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

PACKAGE OUTLINE DRAWINGS
3.00 BSC

0.85
0.075 REF

12

0.10 C ×2

1

1.27
MIN

0.30

12

1

A

2

3.00 BSC

1.00
2.90
0.80
MIN

0.10 C ×2

0.50
0.70

Branded Face
9×

2.05 REFD

SEATING
PLANE

0.08 C
0.50 BSC

C
C

0.75 ±0.05
0.25 NOM ×8

F
1.36
0.60
×2
1.79

0.20
×4

2.70
PCB Layout Reference View10.40±0.10

B
2

0.74

1

1.50 FE

F F2
120.05 REF

1.31

F

NNNN
YYWW
LLLL

Standard Branding Reference View
N = Device part number
Y = Last two digits of year of manufacture
W = Week of manufacture
L = Lot number

F1

2.20

For reference only, not for tooling use (reference JEDEC MO-220WEED
except for fused current path and wettable flank; Allegro DWG-0000382, Rev. 2)
Dimensions in millimeters
Exact case and lead configuration at supplier discretion within limits shown
A Terminal #1 mark area
B Fused sensed current path
C Reference land pattern layout (reference IPC7351
QFN50P300X300X80-17W4M);
All pads a minimum of 0.20 mm from all adjacent pads; adjust as
necessary to meet application process requirements and PCB layout
tolerances; when mounting on a multilayer PCB, thermal vias at the
exposed thermal pad land can improve thermal dissipation (reference
EIA/JEDEC Standard JESD51-5)

D Coplanarity includes exposed current path and terminals
E

Branding scale and appearance at supplier discretion

F

Hall elements (F1 and F2); not to scale

Figure 13: Package EXB, 12-Contact QFNwith Fused Sensed Current Loopand Wettable Flank

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

31Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

For Reference Only – Not for Tooling Use(reference Allegro DWG-0000385, Rev. 2 or JEDEC MS-012AA)
Dimensions in millimeters – NOT TO SCALE
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
8°
0°

4.90 BSC

8

8
D

D1

D2

0.21 ±0.04

D3.90 BSC
D

1.27

0.65

5.60

6.00 BSC

A

1.52

1.75
1

2
0.44

D

1

0.84 +0.43
–0.44

D

2.01

C

2

PCB Layout Reference View

0.25 BSCSEATING PLANE

Branded Face
8×
0.10

1.62

C

+0.13
–0.27

C

GAUGE PLANEXXXXXXXX
Lot Number

SEATING
PLANE

0.15 +0.10–0.05

0.41 ±0.10
1.27 BSC

1

Standard Branding Reference View

A

Terminal #1 mark area

B

Branding scale and appearance at supplier discretion

Line 1, 2: Max. 8 characters per line
Belly Brand: 5 characters

C

Reference land pattern layout (reference IPC7351 SOIC127P600X175-8M);
all pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances.

Line 1: Part NumberLine 3: First 8 characters of Assembly Lot Number
Belly Brand: Country of Origin
Lot Number

D

Hall elements (D1 and D2); not to scale

B

Figure 14: Package LCB, 8-Pin SOIC

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

32

Automotive-Grade, Galvanically Isolated Current Sensor IC
with Common-Mode Field Rejection and Overcurrent Detection
in Small Footprint Low-Profile Packages

ACS71240

Revision History
NumberDate

Description–

March 7, 2019

Initial release1

May 31, 2019

Updated TUV certificate mark2

July 24, 2019

Added Hall elements to LC package drawing (page 20)

3August 21, 2019

Added Maximum Continuous Current to Absolute Maximum Ratings table (page 2),
ESD ratings table (page 2), and thermal data section (pages 17-18)

4October 4, 2019

Added Comparative Tracking Index to Isolation Characteristics table (page 3), and Characteristic
Performance Data charts (pages 13-15)

5December 6, 2019

Added -030B5 part variant (pages 2, 10), Output Slew Rate characteristic (page 6), TypicalFrequency Response note (page 16)

6

December 19, 2019

Added -030B3-167L part variant; updated Rise Time, Response Time, Propagation Delay, and
Output Slew Rate test conditions, and Output Slew Rate value.

April 20, 2020

Added Primary Conductor Inductance values (page 6); removed FAULT Operating Point from
Common Electrical Characteristics table (page 7); added FAULT Operating Point to Performance
Characteristics tables (pages 8-13); updated Frequency Response (page 14); added Response
Characteristics Definitions and Performance Data application page (page 15); added Power on
Functional Description and Performance Data application page (page 16)

March 18, 2021

Added KEX-10B5 part variant (pages 2, 10); added KEX-020B5 and KEX-020B5-150L part variants(pages 2, 11); added KEX-045B5 variant (pages 2,13); added KEX-050B5 part variant (pages 2,14); added LLC-025B3 variant (pages 2, 16); added LLC-050B3 (pages 2, 17); added LLC-20U5
part variant (pages 2, 18); added LLC-050B5 part variant (pages 2, 19); updated ESD Ratings table
Test Conditions (page 3); added extended sensing range equation to footnote [3] of the Common
Electrical Characteristics table (page 7); added footnote [4] to FAULT Current Hysteresis in the
Common Electrical Characteristics table (page 7); updated Fault Behavior application section(page 26)

9April 23, 2021

Added KEX-50B3 part variant (pages 2, 10)

10June 29, 2021

Added KEX-50B3-120 part variant (pages 2, 10)

11

July 27,2021

Added -S lead free part variants (all pages)

12

September 15, 2022

Updated package drawings (pages 31-32)

7

8

Copyright 2022, Allegro MicroSystems.
Allegro MicroSystems reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit
improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the
information being relied upon is current.
Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure ofAllegro’s product can reasonably be expected to cause bodily harm.
The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems assumes no responsibility for its use; nor
for any infringement of patents or other rights of third parties which may result from its use.
Copies of this document are considered uncontrolled documents.

For the latest version of this document, visit our website:www.allegromicro.com

Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com

33