Not to scale
The Allegro™ ACS722 current sensor IC is an economical and
precise solution for AC or DC current sensing in industrial,
commercial, and communications systems. The small package
is ideal for space constrained applications while also saving
costs due to reduced board area. Typical applications include
motor control, load detection and management, switched-mode
power supplies, and overcurrent fault protection.
The device consists of a precise, low-offset, 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 field to the Hall transducer. A precise, proportional
voltage is provided by the low-offset, chopper-stabilized
BiCMOS Hall IC, which includes Allegro’s patented digital
temperature compensation, resulting in extremely accurate
performance over temperature. The output of the device has
a positive slope when an increasing current flows through the
primary copper conduction path (from pins 1 and 2, to pins 3
and 4), which is the path used for current sensing. The internal
resistance of this conductive path is 0.65 mΩ typical, providing
low power loss.
The terminals of the conductive path are electrically isolated
from the sensor leads (pins 5 through 8). This allows the
ACS722 current sensor IC to be used in high-side current sense
applications without the use of high-side differential amplifiers
or other costly isolation techniques.
The ACS722 is provided in a small, low profile surface mount
SOIC8 package. The leadframe is plated with 100% matte tin,
ACS722-DS, Rev. 3
MCO-0000537
• Patented integrated digital temperature compensation
circuitry allows for near closed loop accuracy over
temperature in an open loop sensor
• UL60950-1 (ed. 2) certified
□Dielectric Strength Voltage = 2.4 kVrms
□Basic Isolation Working Voltage = 420 Vpk/297
Vrms
• Industry-leading noise performance with greatly
improved bandwidth through proprietary amplifier and
filter design techniques
• Pin-selectable band width: 80 kHz for high bandwidth
applications or 20 kHz for low noise performance
• 0.65 mΩ primary conductor resistance for low power
loss and high inrush current withstand capability
• Small footprint, low-profile SOIC8 package suitable for
space-constrained applications
• Integrated shield virtually eliminates capacitive coupling
from current conductor to die, greatly suppressing output
noise due to high dv/dt transients
• 3 to 3.6 V, single supply operation
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
Continued on the next page…
Package: 8-pin SOIC (su󰀨 ix LC)
Typical Application
P
P
P
L
CBYPASS
0.1 µF
ACS722
C
2
1
3
4
6
8
5
7
IP+ VCC
–I
+I
IP+ VIOUT
IP–
IP–
BW_SEL
GND
I
The ACS722 outputs an analog
signal, VIOUT , that changes,
proportionally, with the
bidirectional AC or DC primary
sensed current, IP , within
the specified measurement
range. The BW_SEL pin can
be used to select one of the
two bandwidths to optimize the
noise performance. Grounding
the BW_SEL pin puts the part
in the high bandwidth (80 kHz)
mode.
Continued on the next page…
FEATURES AND BENEFITS DESCRIPTION
ACS722
December 11, 2018
TÜV America
Certificate Number:
U8V 18 02 54214 041
CB 14 11 54214 031
UL Certied File
No.: US-32848-UL
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
2
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Selection Guide
Part Number IPR (A)
Sens(Typ)
at VCC = 3.3 V
(mV/A)
TA (°C) Packing1
ACS722LLCTR-05AB-T2±5 264
-40 to 150 Tape and Reel, 3000 pieces per reel
ACS722LLCTR-10AU-T210
ACS722LLCTR-10AB-T2±10 132
ACS722LLCTR-20AU-T220
ACS722LLCTR-20AB-T2±20 66
ACS722LLCTR-40AU-T240
ACS722LLCTR-40AB-T2±40 33
1Contact Allegro for additional packing options.
2Variant not intended for automotive applications.
which is compatible with standard lead (Pb) free printed circuit
board 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.
Description (continued)
• Output voltage proportional to AC or DC current
• Factory-trimmed sensitivity and quiescent output voltage for
improved accuracy
• Chopper stabilization results in extremely stable quiescent
output voltage
• Nearly zero magnetic hysteresis
• Ratiometric output from supply voltage
Features and Benefits (continued)
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
3
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Thermal Characteristics
Characteristic Symbol Test Conditions* Value Units
Package Thermal Resistance
(Junction to Ambient) RθJA
Mounted on the Allegro 85-0593 evaluation board with 400 mm2 of
4 oz. copper on each side, connected to pins 1 and 2, and to pins 3
and 4, with thermal vias connecting the layers. Performance values
include the power consumed by the PCB.
23 ºC/W
Package Thermal Resistance
(Junction to Lead) RθJL Mounted on the Allegro ASEK 722 evaluation board. 5 ºC/W
*Additional thermal information available on the Allegro website.
Isolation Characteristics
Characteristic Symbol Notes Rating Unit
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 UL 60950-1 (edition 2).
420 VPK or VDC
297 VRMS
Clearance Dcl Minimum distance through air from IP leads to signal leads. 3.9 mm
Creepage Dcr Minimum distance along package body from IP leads to
signal leads. 3.9 mm
Absolute Maximum Ratings
Characteristic Symbol Notes Rating Units
Supply Voltage VCC 6 V
Reverse Supply Voltage VRCC –0.1 V
Output Voltage VIOUT 25 V
Reverse Output Voltage VRIOUT –0.1 V
Operating Ambient Temperature TARange L –40 to 150 °C
Junction Temperature TJ(max) 165 °C
Storage Temperature Tstg –65 to 165 °C
SPECIFICATIONS
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
4
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Dynamic Offset
Cancellation
Master Current
Supply Programming
Control
EEPROM and
Control Logic
Offset
Control
Sensitivity
Control
Tuned
Filter
Temperature
Sensor
Hall
Current
Drive
POR
To All Subcircuits
IP+
IP+
IP–
IP–
VCC
VIOUT
GND
BW_SEL
Functional Block Diagram
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
5
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Terminal List Table
Number Name Description
1, 2 IP+ Terminals for current being sensed; fused internally
3, 4 IP– Terminals for current being sensed; fused internally
5 GND Signal ground terminal
6 BW_SEL Terminal for selecting 20 kHz or 80 kHz bandwidth
7 VIOUT Analog output signal
8 VCC Device power supply terminal
IP+
IP+
IP–
IP–
VCC
VIOUT
BW_SEL
GND
1
2
3
4
8
7
6
5
Pin-out Diagram
Pin-out Diagram and Terminal List
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
6
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
COMMON ELECTRICAL CHARACTERISTICS1: valid through the full range of TA = –40°C to 150°C
, and at VCC
=
3.3 V; unless otherwise specif ied
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Supply Voltage VCC 3 3.3 3.6 V
Supply Current ICC VCC within VCC(min) and VCC(max) – 9 12 mA
Output Capacitance Load CLVIOUT to GND – – 10 nF
Output Resistive Load RLVIOUT to GND 4.7 – – kΩ
Primary Conductor Resistance RIP TA = 25°C – 0.65 – mΩ
Magnetic Coupling Factor CF– 10 – G/A
Rise Time tr
IP = IP(max), TA = 25°C, CL = 1 nF,
BW_SEL tied to GND – 4 – μs
IP = IP(max), TA = 25°C, CL = 1 nF,
BW_SEL tied to VCC – 17.5 – μs
Propagation Delay tpd
IP = IP(max), TA = 25°C, CL = 1 nF,
BW_SEL tied to GND – 1 – μs
IP = IP(max), TA = 25°C, CL = 1 nF,
BW_SEL tied to VCC – 5 – μs
Response Time tRESPONSE
IP = IP(max), TA = 25°C, CL = 1 nF,
BW_SEL tied to GND – 5 – μs
IP = IP(max), TA = 25°C, CL = 1 nF,
BW_SEL tied to VCC – 22.5 – μs
Internal Bandwidth BWi
Small signal –3 dB; CL = 1 nF,
BW_SEL tied to GND – 80 – kHz
Small signal –3 dB; CL = 1nF,
BW_SEL tied to VCC – 20 – kHz
Noise Density IND Input referenced noise density;
TA = 25°C, CL = 1 nF – 150 – µA(rms)/
√Hz
Noise IN
Input referenced noise; BWi = 80 kHz,
TA = 25°C, CL = 1 nF – 42 – mA(rms)
Input referenced noise; BWi = 20 kHz,
TA = 25°C, CL = 1 nF – 21 – mA(rms)
Nonlinearity ELIN Through full range of IP– ±1 %
Saturation Voltage2VOH RL = 4.7 kΩ, TA = 25°C VCC –
0.33 – – V
VOL RL = 4.7 kΩ, TA = 25°C – – 0.33 V
Power-On Time tPO Output reaches 90% of steady-state
level, TA = 25°C, IP = IPR(max) applied – 64 – μs
1Device may be operated at higher primary current levels, IP , ambient temperatures, TA , and internal leadframe temperatures, provided the Maximum Junction Tem-
perature, TJ(max), is not exceeded.
2The sensor IC will continue to respond to current beyond the range of IP until the high or low saturation voltage; however, the nonlinearity in this region will be
worse than through the rest of the measurement range.
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
7
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-5AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless oth-
erwise specif ied
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Nominal Performance
Current Sensing Range IPR –5 – 5 A
Sensitivity Sens IPR(min) < IP < IPR(max) – 264 – mV/A
Zero Current Output Voltage VIOUT(Q) Bidirectional; IP = 0 A – VCC x
0.5 – V
Accuracy Performance
Sensitivity Error Esens
TA = 25°C to 150°C; measured at IP = IPR(max) –2 – 2 %
TA = –40°C to 25°C; ; measured at IP = IPR(max) – ±2.5 – %
Offset Voltage1VOE
IP = 0 A; TA = 25°C to 150°C –15 – 15 mV
IP = 0 A; TA = -40°C to 25°C – ±20 – mV
Total Output Error2ETOT
IP = IPR(max), TA = 25°C to 150°C –2.5 – 2.5 %
IP = IPR(max), TA = –40°C to 25°C – ±3 – %
Lifetime Drift Characteristics
Sensitivity Error Lifetime Drift Esens_drift – ±2 – %
Total Output Error Lifetime
Drift Etot_drift – ±2 – %
1 Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields.
2 Percentage of IP
, with IP = IPR(max)
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
8
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-10AU PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless
otherwise specif ied
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Nominal Performance
Current Sensing Range IPR 0 – 10 A
Sensitivity Sens IPR(min) < IP < IPR(max) – 264 – mV/A
Zero Current Output Voltage VIOUT(Q) Unidirectional; IP = 0 A – VCC x
0.1 – V
Accuracy Performance
Sensitivity Error Esens
TA = 25°C to 150°C; measured at IP = IPR(max) –2 – 2 %
TA = –40°C to 25°C; ; measured at IP = IPR(max) – ±2.5 – %
Offset Voltage1VOE
IP = 0 A; TA = 25°C to 150°C –15 – 15 mV
IP = 0 A; TA = -40°C to 25°C – ±20 – mV
Total Output Error2ETOT
IP = IPR(max), TA = 25°C to 150°C –2.5 – 2.5 %
IP = IPR(max), TA = –40°C to 25°C – ±3 – %
Lifetime Drift Characteristics
Sensitivity Error Lifetime Drift Esens_drift – ±2 – %
Total Output Error Lifetime
Drift Etot_drift – ±2 – %
1 Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields.
2 Percentage of IP
, with IP = IPR(max)
xLLCTR-10AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless
otherwise specif ied
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Nominal Performance
Current Sensing Range IPR –10 – 10 A
Sensitivity Sens IPR(min) < IP < IPR(max) – 132 – mV/A
Zero Current Output Voltage VIOUT(Q) Bidirectional; IP = 0 A – VCC x
0.5 – V
Accuracy Performance
Sensitivity Error Esens
TA = 25°C to 150°C; measured at IP = IPR(max) –1.5 – 1.5 %
TA = –40°C to 25°C; ; measured at IP = IPR(max) – ±2 – %
Offset Voltage1VOE
IP = 0 A; TA = 25°C to 150°C –10 – 10 mV
IP = 0 A; TA = -40°C to 25°C – ±15 – mV
Total Output Error2ETOT
IP = IPR(max), TA = 25°C to 150°C –2 – 2 %
IP = IPR(max), TA = –40°C to 25°C – ±3 – %
Lifetime Drift Characteristics
Sensitivity Error Lifetime Drift Esens_drift – ±2 – %
Total Output Error Lifetime
Drift Etot_drift – ±2 – %
1 Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields.
2 Percentage of IP
, with IP = IPR(max)
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
9
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-20AU PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless
otherwise specif ied
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Nominal Performance
Current Sensing Range IPR 0 – 20 A
Sensitivity Sens IPR(min) < IP < IPR(max) – 132 – mV/A
Zero Current Output Voltage VIOUT(Q) Unidirectional; IP = 0 A – VCC x
0.1 – V
Accuracy Performance
Sensitivity Error Esens
TA = 25°C to 150°C; measured at IP = IPR(max) –1.5 – 1.5 %
TA = –40°C to 25°C; ; measured at IP = IPR(max) – ±2 – %
Offset Voltage1VOE
IP = 0 A; TA = 25°C to 150°C –10 – 10 mV
IP = 0 A; TA = -40°C to 25°C – ±15 – mV
Total Output Error2ETOT
IP = IPR(max), TA = 25°C to 150°C –2 – 2 %
IP = IPR(max), TA = –40°C to 25°C – ±3 – %
Lifetime Drift Characteristics
Sensitivity Error Lifetime Drift Esens_drift – ±2 – %
Total Output Error Lifetime
Drift Etot_drift – ±2 – %
1 Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields.
2 Percentage of IP
, with IP = IPR(max)
xLLCTR-20AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless
otherwise specif ied
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Nominal Performance
Current Sensing Range IPR –20 – 20 A
Sensitivity Sens IPR(min) < IP < IPR(max) – 66 – mV/A
Zero Current Output Voltage VIOUT(Q) Bidirectional; IP = 0 A – VCC x
0.5 – V
Accuracy Performance
Sensitivity Error Esens
TA = 25°C to 150°C; measured at IP = IPR(max) –1.5 – 1.5 %
TA = –40°C to 25°C; ; measured at IP = IPR(max) – ±2 – %
Offset Voltage1VOE
IP = 0 A; TA = 25°C to 150°C –10 – 10 mV
IP = 0 A; TA = -40°C to 25°C – ±15 – mV
Total Output Error2ETOT
IP = IPR(max), TA = 25°C to 150°C –2 – 2 %
IP = IPR(max), TA = –40°C to 25°C – ±3 – %
Lifetime Drift Characteristics
Sensitivity Error Lifetime Drift Esens_drift – ±2 – %
Total Output Error Lifetime
Drift Etot_drift – ±2 – %
1 Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields.
2 Percentage of IP
, with IP = IPR(max)
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
10
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-40AU PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless
otherwise specif ied
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Nominal Performance
Current Sensing Range IPR 0 – 40 A
Sensitivity Sens IPR(min) < IP < IPR(max) – 66 – mV/A
Zero Current Output Voltage VIOUT(Q) Unidirectional; IP = 0 A – VCC x
0.1 – V
Accuracy Performance
Sensitivity Error Esens
TA = 25°C to 150°C; measured at IP = IPR(max) –1.5 – 1.5 %
TA = –40°C to 25°C; ; measured at IP = IPR(max) – ±2 – %
Offset Voltage1VOE
IP = 0 A; TA = 25°C to 150°C –10 – 10 mV
IP = 0 A; TA = -40°C to 25°C – ±15 – mV
Total Output Error2ETOT
IP = IPR(max), TA = 25°C to 150°C –2 – 2 %
IP = IPR(max), TA = –40°C to 25°C – ±3 – %
Lifetime Drift Characteristics
Sensitivity Error Lifetime Drift Esens_drift – ±2 – %
Total Output Error Lifetime
Drift Etot_drift – ±2 – %
1 Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields.
2 Percentage of IP
, with IP = IPR(max)
xLLCTR-40AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless
otherwise specif ied
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Nominal Performance
Current Sensing Range IPR –40 – 40 A
Sensitivity Sens IPR(min) < IP < IPR(max) – 33 – mV/A
Zero Current Output Voltage VIOUT(Q) Bidirectional; IP = 0 A – VCC x
0.5 – V
Accuracy Performance
Sensitivity Error Esens
TA = 25°C to 150°C; measured at IP = IPR(max) –1.5 – 1.5 %
TA = –40°C to 25°C; ; measured at IP = IPR(max) – ±2 – %
Offset Voltage1VOE
IP = 0 A; TA = 25°C to 150°C –10 – 10 mV
IP = 0 A; TA = -40°C to 25°C – ±15 – mV
Total Output Error2ETOT
IP = IPR(max), TA = 25°C to 150°C –2 – 2 %
IP = IPR(max), TA = –40°C to 25°C – ±3 – %
Lifetime Drift Characteristics
Sensitivity Error Lifetime Drift Esens_drift – ±2 – %
Total Output Error Lifetime
Drift Etot_drift – ±2 – %
1 Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields.
2 Percentage of IP
, with IP = IPR(max)
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
11
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
CHARACTERISTIC PERFORMANCE
Zero Current Output Voltage vs. Temperature
Offset Voltage vs. Temperature
Sensitivity vs. Temperature
Nonlinearity vs. Temperature Total Error at I vs. Temperature
PR(max)
Sensitivity Error vs. Temperature
Temperature (ºC)
Offset Voltage (mV)
-50 -50
-50
-50
-50
-50
00
0
0
0
0
50 50
50
50
50
50
100 100
100
100
100
100
150 150
150
150
150
150
Temperature (ºC)
1600
258 -4
1610
260 -3
1620
262 -2
1630
264 -1
1660
270 2
1640
266 0
1670
272 3
1650
268 1
1680
274 4
V (mV)
IOUT(Q)
Temperature (ºC)
Sensitivity (mV/A)
Temperature (ºC)
Sensitivity Error (%)
Temperature (ºC)
Total Error (%)
Temperature (ºC)
Nonlinearity (%)
-1.00 -5
-0.80 -4
-0.40 -2
-0.20 -1
0.00 0
0.20 1
0.80 4
0.60 3
1.00 5
+3 Sigma Average -3 Sigma
-50
-40
-30
-20
10
-10
20
0
30
0.40 2
-0.60 -3
xLLCTR-5AB Key Parameters
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
12
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Zero Current Output Voltage vs. Temperature
Offset Voltage vs. Temperature
Sensitivity vs. Temperature
Nonlinearity vs. Temperature Total Error at I vs. Temperature
PR(max)
Sensitivity Error vs. Temperature
Temperature (ºC)
Offset Voltage (mV)
-50 -50
-50
-50
-50
-50
00
0
0
0
0
50 50
50
50
50
50
100 100
100
100
100
100
150 150
150
150
150
150
Temperature (ºC)
1635 -15
129 -4
130 -3
1640 -10
131 -2
1645 -5
132 -1
1655 5
135 2
133 0
136 3
1650 0
134 1
1660 10
137 4
V (mV)
IOUT(Q)
Temperature (ºC)
Sensitivity (mV/A)
Temperature (ºC)
Sensitivity Error (%)
Temperature (ºC)
Total Error (%)
Temperature (ºC)
Nonlinearity (%)
-1.00 -5
-0.80 -4
-0.40 -2
-0.20 -1
0.00 0
0.20 1
0.80 4
0.60 3
1.00 5
+3 Sigma Average -3 Sigma
0.40 2
-0.60 -3
xLLCTR-10AB Key Parameters
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
13
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Zero Current Output Voltage vs. Temperature
Offset Voltage vs. Temperature
Sensitivity vs. Temperature
Nonlinearity vs. Temperature Total Error at I vs. Temperature
PR(max)
Sensitivity Error vs. Temperature
Temperature (ºC)
Offset Voltage (mV)
-50 -50
-50
-50
-50
-50
00
0
0
0
0
50 50
50
50
50
50
100 100
100
100
100
100
150 150
150
150
150
150
Temperature (ºC)
256
300 -30
-4
258
305 -25
-3
262
310 -20
-2
264
315 -15
-1
272
330 0
2
266
320 -10
0
274
335 5
3
268
325 -5
1
276
340 10
5
V (mV)
IOUT(Q)
Temperature (ºC)
Sensitivity (mV/A)
Temperature (ºC)
Sensitivity Error (%)
Temperature (ºC)
Total Error (%)
Temperature (ºC)
Nonlinearity (%)
-1.00 -5
-0.80 -4
-0.40 -2
-0.20 -1
0.00 0
0.20 1
0.80 4
0.60 3
1.00 5
+3 Sigma Average -3 Sigma
0.40 2
-0.60 -3
270
260
4
xLLCTR-10AU Key Parameters
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
14
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Zero Current Output Voltage vs. Temperature
Offset Voltage vs. Temperature
Sensitivity vs. Temperature
Nonlinearity vs. Temperature Total Error at I vs. Temperature
PR(max)
Sensitivity Error vs. Temperature
Temperature (ºC)
Offset Voltage (mV)
-50 -50
-50
-50
-50
-50
00
0
0
0
0
50 50
50
50
50
50
100 100
100
100
100
100
150 150
150
150
150
150
Temperature (ºC)
65
1634 1634
-4
65
1636 1636
-3
66
1638 1638
-2
67
1640 1640
-1
68
1648 1648
2
1644 1644
0
69
1650 1650
3
67
1646 1646
1
69
1652 1652
5
V (mV)
IOUT(Q)
Temperature (ºC)
Sensitivity (mV/A)
Temperature (ºC)
Sensitivity Error (%)
Temperature (ºC)
Total Error (%)
Temperature (ºC)
Nonlinearity (%)
-1.00 -6
-0.80
-4
-0.40 -2
-0.20
0.00 0
0.20
0.80
4
0.60
1.00 6
+3 Sigma Average -3 Sigma
0.40 2
-0.60
68
66
4
1642 1642
xLLCTR-20AB Key Parameters
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
15
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Zero Current Output Voltage vs. Temperature
Offset Voltage vs. Temperature
Sensitivity vs. Temperature
Nonlinearity vs. Temperature Total Error at I vs. Temperature
PR(max)
Sensitivity Error vs. Temperature
Temperature (ºC)
Offset Voltage (mV)
-50 -50
-50
-50
-50
-50
0
0
0
0
0
0
50
50
50
50
50
50
100
100
100
100
100
100
150
150
150
150
150
150
Temperature (ºC)
129
310 -20
-4
130
315 -15
-3
132
-2
133
320 -10
-1
137
2
325 -5
0
138
335 5
3
135
330 0
1
139
340 10
5
V (mV)
IOUT(Q)
Temperature (ºC)
Sensitivity (mV/A)
Temperature (ºC)
Sensitivity Error (%)
Temperature (ºC)
Total Error (%)
Temperature (ºC)
Nonlinearity (%)
-1.00 -5
-0.80 -4
-0.40 -2
-0.20 -1
0.00 0
0.20 1
0.80 4
0.60 3
1.00 5
+3 Sigma Average -3 Sigma
0.40 2
-0.60 -3
136
131
4
134
xLLCTR-20AU Key Parameters
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
16
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Zero Current Output Voltage vs. Temperature
Offset Voltage vs. Temperature
Sensitivity vs. Temperature
Nonlinearity vs. Temperature Total Error at I vs. Temperature
PR(max)
Sensitivity Error vs. Temperature
Temperature (ºC)
Offset Voltage (mV)
-50 -50
-50
-50
-50
-50
0
0
0
0
0
0
50
50
50
50
50
50
100
100
100
100
100
100
150
150
150
150
150
150
Temperature (ºC)
32
1634 -16
-4
1636 -14
-3
33
1640 -10
-2
1642 -8
-1
35
1650 0
2
0
1652 2
3
1646 -4
1
35
1654 4
6
V (mV)
IOUT(Q)
Temperature (ºC)
Sensitivity (mV/A)
Temperature (ºC)
Sensitivity Error (%)
Temperature (ºC)
Total Error (%)
Temperature (ºC)
Nonlinearity (%)
-1.00 -5
-0.80 -4
-0.40 -2
-0.20 -1
0.00 0
0.20 1
0.80 4
0.60 3
1.00 5
+3 Sigma Average -3 Sigma
0.40 2
-0.60 -3
34
1648 -2
33
1638 -12
4
34
1644 -6
5
xLLCTR-40AB Key Parameters
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
17
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Zero Current Output Voltage vs. Temperature
Offset Voltage vs. Temperature
Sensitivity vs. Temperature
Nonlinearity vs. Temperature Total Error at I vs. Temperature
PR(max)
Sensitivity Error vs. Temperature
Temperature (ºC)
Offset Voltage (mV)
-50 -50
-50
-50
-50
-50
0
0
0
0
0
0
50
50
50
50
50
50
100
100
100
100
100
100
150
150
150
150
150
150
Temperature (ºC)
65
310 -20
-4
315 -15
-3
66
320 -10
-2
325 -5
-1
69
2
0
340 10
3
330 0
1
69
345 15
V (mV)
IOUT(Q)
Temperature (ºC)
Sensitivity (mV/A)
Temperature (ºC)
Sensitivity Error (%)
Temperature (ºC)
Total Error (%)
Temperature (ºC)
Nonlinearity (%)
-1.00 -5
-0.80 -4
-0.40 -2
-0.20 -1
0.00 0
0.20 1
0.80 4
0.60 3
1.00 5
+3 Sigma Average -3 Sigma
0.40 2
-0.60 -3
68
335 5
65
4
67
5
68
67
66
xLLCTR-40AU Key Parameters
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
18
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Sensitivity (Sens)
The change in sensor IC output in response to a 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 sen-
sor IC is over the full current measurement range. The nonlinear-
ity is calculated as:
1–
[{
[{
VIOUT
(IPR(max)) – VIOUT(Q) × 100 (%)
ELIN = 2 × VIOUT
(IPR(max)/2) – VIOUT(Q)
where VIOUT(IPR(max)) is the output of the sensor IC with the
maximum measurement current flowing through it and
VIOUT(IPR(max)/2) is the output of the sensor IC with half of the
maximum measurement current flowing through it.
Zero Current Output Voltage (VIOUT(Q))
The output of the sensor when the primary current is zero. For
a unipolar supply voltage, it nominally remains at 0.5 × VCC for
a bidirectional device and 0.1 × VCC for a unidirectional device.
For example, in the case of a bidirectional output device, VCC =
3.3 V translates into VIOUT(Q) = 1.65 V. Variation in VIOUT(Q) can
be attributed to the resolution of the Allegro linear IC quiescent
voltage trim and thermal drift.
Offset Voltage (VOE)
The deviation of the device output from its ideal quiescent value
of 0.5 × VCC (bidirectional) or 0.1 × VCC (unidirectional) due to
nonmagnetic causes. To convert this voltage to amperes, divide
by the device sensitivity, Sens.
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:
E
TOT
(I
P
)
V
IOUT_ideal
(I
P
) – V
IOUT
(I
P
)
Sens
ideal
(I
P
)
×
I
P
×
100 (%)=
The Total Output Error incorporates all sources of error and is a
function of IP . At relatively high currents, ETOT will be mostly
DEFINITIONS OF ACCURACY CHARACTERISTICS
Figure 1: Output Voltage versus Sensed Current
Figure 2: Total Output Error versus Sensed Current
0 A
Decreasing
VIOUT (V)
Accuracy Across
Temperature
Accuracy Across
Temperature
Accuracy Across
Temperature
Accuracy at
25°C Only
Accuracy at
25°C Only
Accuracy at
25°C Only
Increasing
VIOUT (V)
Ideal VIOUT
IPR(min)
IPR(max)
+IP (A)
–IP (A)
VIOUT(Q)
Full Scale IP
+IP
–IP
+ETOT
–ETOT
Across Temperature
25°C Only
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 Figures
1 and 2. Figure 1 shows a distribution of output voltages versus IP
at 25°C and across temperature. Figure 2 shows the correspond-
ing ETOT versus IP .
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
19
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Impact of External Magnetic Fields
The ACS722 works by sensing the magnetic field created by the
current flowing through the package. However, the sensor cannot
differentiate between fields created by the current flow and exter-
nal magnetic fields. This means that external magnetic fields can
cause errors in the output of the sensor. Magnetic fields which are
perpendicular to the surface of the package affect the output of
the sensor, as it only senses fields in that one plane. The error in
Amperes can be quantified as:
Error(B) =
B
CF
where B is the strength of the external field perpendicular to the
surface of the package in Gauss, and CF is the coupling factor in
G/A. Then, multiplying by the sensitivity of the part, Sens, gives
the error in mV.
For example, an external field of 1 Gauss will result in around
0.1 A of error. If the ACS722LLCTR-10AB, which has a nominal
sensitivity of 132 mV/A, is being used, that equates to 13.2 mV
of error on the output of the sensor.
External Field
(Gauss) Error (A) Error (mV)
5AB 10AB 20AB 40AB
0.5 0.05 13.2 6.6 3.3 1.65
1 0.1 26.4 13.2 6.6 3.3
2 0.2 52.8 26.4 13.2 6.6
APPLICATION INFORMATION
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
20
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
DEFINITIONS OF DYNAMIC RESPONSE CHARACTERISTICS
Power-On Time (tPO)
When the supply is ramped to its operating voltage, the device
requires a finite time to power its internal components before
responding to an input magnetic field.
Power-On Time, tPO , is defined as the time it takes for the output
voltage to settle within ±10% of its steady state value under an
applied magnetic field, after the power supply has reached its
minimum specified operating voltage, VCC(min), as shown in the
chart at right.
Rise Time (tr)
The time interval between a) when the sensor IC reaches 10% of
its full scale value, and b) when it reaches 90% of its full scale
value. The rise time to a step response is used to derive the band-
width of the current sensor IC, in which ƒ(–3 dB) = 0.35 / tr. Both
tr and tRESPONSE are detrimentally affected by eddy current losses
observed in the conductive IC ground plane.
Propagation Delay (tpd
)
The propagation delay is measured as the time interval a) when
the primary current signal reaches 20% of its final value, and b)
when the device reaches 20% of its output corresponding to the
applied current.
Response Time (tRESPONSE)
The time interval between a) when the primary current signal
reaches 90% of its final value, and b) when the device reaches
90% of its output corresponding to the applied current.
VIOUT
V
t
VCC
VCC(min.)
90% VIOUT
0
t1= time at which power supply reaches
minimum specified operating voltage
t2=
time at which output voltage settles
within ±10% of its steady state value
under an applied magnetic field
t1t2
tPO
V
CC
(typ.)
Primary Current
VIOUT
90
0
(%)
Response Time, tRESPONSE
t
Primary Current
VIOUT
90
10
20
0
(%)
Propagation Delay, tpd
Rise Time, tr
t
Figure 3: Power-On Time (tPO)
Figure 4: Rise Time (tr) and Propagation Delay (tpd
)
Figure 5: Response Time (tRESPONSE)
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
21
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Figure 6: Package LC, 8-pin SOICN
C
1.27 BSC
A
B
B
C
21
8
Branding scale and appearance at supplier discretion
C
SEATING
PLANE
C0.10
8X
0.25 BSC
1.04 REF
1.75 MAX
1.75
4.90 ±0.10
3.90 ±0.10 6.00 ±0.20
0.51
0.31 0.25
0.10
0.25
0.17
1.27
0.40
8°
0°
A
Standard Branding Reference V
iew
21
1
8
C
0.65 1.27
5.60
Branded Face
For Reference Only – Not for Tooling Use
(Reference 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
SEATING PLANE
GAUGE PLANE
PCB Layout Reference View
NNNNNNN
TPP-AAA
LLLLL
N = Device part number
T= Device temperature range
P= Package Designator
A=Amperage
L= Lot number
Belly Brand = Country of Origin
Terminal #1 mark area
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
Package Outline Drawing
High Accuracy, Galvanically Isolated Current Sensor IC
With Small Footprint SOIC8 Package
ACS722
22
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
For the latest version of this document, visit our website:
www.allegromicro.com
Revision History
Revision Revision Date Description of Revision
– June 10, 2014 Initial release.
1 October 29, 2014 Added Magnetic Coupling Factor characteristic and Error Due to External Magnetic Fields section
2 April 29, 2015 Added Characteristic Performance graphs
3 December 11, 2018 Updated certificate numbers
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Allegro MicroSystems, LLC 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
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