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ACS725 Datasheet

Allegro MicroSystems, LLC

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Datasheet

The Allegro ACS725 current sensor IC is an economical and
precise solution for AC or DC current sensing in industrial,
automotive, 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. The current is sensed differentially in order to reject
common-mode fields, improving accuracy in magnetically
noisy environments. The inherent 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 is
programmed for accuracy after packaging. 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 1.2 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
ACS725 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.
ACS725-DS, Rev. 12
MCO-0000160
AEC-Q100 qualified
Differential Hall sensing rejects common-mode fields
1.2 mΩ primary conductor resistance for low power loss
and high inrush current withstand capability
Integrated shield virtually eliminates capacitive coupling
from 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 and
filter design techniques
High-bandwidth 120 kHz analog output for faster
response times in control applications
Filter pin allows user to filter the output for improved
resolution at lower bandwidth
Patented integrated digital temperature compensation
circuitry allows for near closed loop accuracy over
temperature in an open-loop sensor
Small footprint, low-profile SOIC8 package suitable for
space-constrained applications
Filter pin simplifies bandwidth limiting for better
resolution at lower frequencies
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
Continued on the next page…
Typical Application
CBYPASS
0.1 µF
CF
1 nF
ACS725
CLOAD
IP
+IP
–IP
1
2
3
4
IP+
IP+
IP–
IP–
VCC
VIOUT
FILTER
GND
8
7
6
5
The ACS725 outputs an
analog signal, VIOUT , that
changes, proportionally,
with the bidirectional AC
or DC primary sensed
current, IP , within the
specified measurement
range. The FILTER pin
can be used to decrease
the bandwidth in order
to optimize the noise
performance.
FEATURES AND BENEFITS DESCRIPTION
PACKAGE: 8-Pin SOIC (suffix LC)
CB Certificate Number:
US-32848-UL
TÜV America
Certificate Number:
U8V 18 02 54214 041
CB 14 11 54214 031
Type
tested
Continued on the next page…
Not to scale
ACS725
December 13, 2018
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
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) Packing [1]
ACS725LLCTR-05AB-T ±5 264
–40 to 150 Tape and Reel, 3000 pieces per reel
ACS725LLCTR-10AB-T ±10 132
ACS725LLCTR-10AU-T 10 264
ACS725LLCTR-20AB-T ±20 66
ACS725LLCTR-20AU-T 20 132
ACS725LLCTR-30AB-T ±30 44
ACS725LLCTR-30AB-T-H [2] ±30 44
ACS725LLCTR-30AU-T 30 88
ACS725LLCTR-40AB-T ±40 33
ACS725LLCTR-50AB-T ±50 26.4
[1] Contact Allegro for additional packing options.
[2] -H denotes 100% cold calibration at the Allegro factory for improved accuracy.
The ACS725 is provided in a small, low-profile surface-mount
SOIC8 package. The leadframe is plated with 100% matte tin,
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.
FEATURES AND BENEFITS (continued) DESCRIPTION (continued)
3.3 V, single supply operation
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
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
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 85-0140 evaluation board with
800 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 °C/W
Package Thermal Resistance
(Junction to Lead) RθJL Mounted on the Allegro ASEK725 evaluation board. 5 °C/W
*Additional thermal information available on the Allegro website.
ISOLATION CHARACTERISTICS
Characteristic Symbol Notes Rating Unit
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 standard 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 4.2 mm
Creepage Dcr Minimum distance along package body from IP leadds to
signal leads 4.2 mm
ABSOLUTE MAXIMUM RATINGS
Characteristic Symbol Notes Rating Units
Supply Voltage VCC 6 V
Reverse Supply Voltage VRCC –0.1 V
Output Voltage VIOUT VCC + 0.5 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
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
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
Temperature
Sensor
Hall
Current
Drive
POR
To All Subcircuits
IP+
IP+
IP
IP
VCC
VCC
VIOUT
CBYPASS
0.1 µF
FILTER
RF(int)
GND CF
+
+
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 FILTER Terminal for external capacitor that sets bandwidth
7 VIOUT Analog output signal
8 VCC Device power supply terminal
Functional Block Diagram
Package LC, 8-Pin SOICN
Pinout Diagram
IP+
IP+
IP–
IP–
VCC
VIOUT
FILTER
GND
1
2
3
4
8
7
6
5
Pinout Diagram and Terminal List Table
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
5
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Characteristic Symbol Test Conditions Min. Typ. Max. Unit
Supply Voltage VCC 3 3.3 3.6 V
Supply Current ICC VCC = 3.3 V, output open 10 14 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 1.2 mΩ
Internal Filter Resistance [2] RF(int) 1.8 kΩ
Common Mode Field Rejection Ratio CMFRR Uniform external magnetic field 40 dB
Primary Hall Coupling Factor G1 TA = 25°C 11 – G/A
Secondary Hall Coupling Factor G2 TA = 25°C 2.8 G/A
Hall plate Sensitivity Matching Sensmatch TA = 25°C ±1 %
Rise Time trIP = IP(max), TA = 25°C, CL = 1 nF 3 μs
Propagation Delay tpd IP = IP(max), TA = 25°C, CL = 1 nF 2 μs
Response Time tRESPONSE IP = IP(max), TA = 25°C, CL = 1 nF 4 μs
Bandwidth BW Small signal –3 dB; CL = 1 nF 120 kHz
Noise Density IND Input referenced noise density;
TA = 25°C, CL = 1 nF 200 µA(rms)/
Hz
Noise INInput referenced noise: CF = 4.7 nF,
CL = 1 nF, BW = 18 kHz, TA = 25°C 27 – mA(rms)
Nonlinearity ELIN Through full range of IP–1.5 +1.5 %
Sensitivity Ratiometry Coefficient SENS_RAT_
COEF VCC = 3.0 to 3.6 V, TA = 25°C 1.3
Zero Current Output Ratiometry Coefficient QVO_RAT_
COEF VCC = 3.0 to 3.6 V, TA = 25°C 1
Saturation Voltage [3] VOH RL = 4.7 kΩ – VCC – 0.3 V
VOL RL = 4.7 kΩ 0.3 – V
Power-On Time tPO Output reaches 90% of steady-state
level, TA = 25°C, IP = IPR(max) applied 80 μs
Shorted Output to Ground Current Isc(gnd) TA = 25°C 3.3 mA
Shorted Output to VCC Current Isc(vcc) TA = 25°C 45 mA
[1] Device may be operated at higher primary current levels, IP , ambient temperatures, TA , and internal leadframe temperatures, provided the Maximum Junction Tempera-
ture, TJ(max), is not exceeded.
[2] RF(int) forms an RC circuit via the FILTER pin.
[3] The 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.
COMMON ELECTRICAL CHARACTERISTICS [1]: Valid through the full range of TA , VCC
= 3.3 V, CF = 0, unless otherwise specified
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
6
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-05AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
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) Unidirectional; IP = 0 A VCC ×
0.5 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2.5 ±0.9 2.5 %
IP = IPR(max); TA = –40°C to 25°C –6 ±4 6 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
IP = IPR(max); TA = 25°C to 150°C –1.5 ±0.9 1.5 %
IP = IPR(max); TA = –40°C to 25°C –5.5 ±4 5.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –15 ±5 15 mV
IP = 0 A; TA = –40°C to 25°C –30 ±15 30 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
xLLCTR-10AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
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) Unidirectional; IP = 0 A VCC ×
0.5 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2 ±0.8 2 %
IP = IPR(max); TA = –40°C to 25°C –6 ±4 6 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
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 5.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –10 ±4 10 mV
IP = 0 A; TA = –40°C to 25°C –30 ±15 30 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
7
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 specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
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 ×
0.1 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2.5 ±0.9 2.5 %
IP = IPR(max); TA = –40°C to 25°C –6 ±4 6 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
IP = IPR(max); TA = 25°C to 150°C –2 ±0.9 2 %
IP = IPR(max); TA = –40°C to 25°C –5.5 ±4 5.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –15 ±5 15 mV
IP = 0 A; TA = –40°C to 25°C –30 ±15 30 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
xLLCTR-20AU PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
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 ×
0.1 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2 ±0.8 2 %
IP = IPR(max); TA = –40°C to 25°C –6 ±4 6 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
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 5.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –10 ±4 10 mV
IP = 0 A; TA = –40°C to 25°C –30 ±5 30 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
8
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-30AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
NOMINAL PERFORMANCE
Current Sensing Range IPR –30 – 30 A
Sensitivity Sens IPR(min) < IP < IPR(max) 44 – mV/A
Zero Current Output Voltage VIOUT(Q) Bidirectional; IP = 0 A VCC ×
0.5 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2 ±0.7 2 %
IP = IPR(max); TA = –40°C to 25°C –6 ±4 6 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
IP = IPR(max); TA = 25°C to 150°C –1.5 ±0.7 1.5 %
IP = IPR(max); TA = –40°C to 25°C –5.5 ±4 5.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –10 ±3 10 mV
IP = 0 A; TA = –40°C to 25°C –30 ±5 30 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
xLLCTR-20AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
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 ×
0.5 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2 ±0.8 2 %
IP = IPR(max); TA = –40°C to 25°C –6 ±4 6 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
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 5.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –10 ±4 10 mV
IP = 0 A; TA = –40°C to 25°C –30 ±5 30 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
9
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-30AB-H PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
NOMINAL PERFORMANCE
Current Sensing Range IPR –30 – 30 A
Sensitivity Sens IPR(min) < IP < IPR(max) 44 – mV/A
Zero Current Output Voltage VIOUT(Q) Bidirectional; IP = 0 A VCC ×
0.5 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2 ±0.7 2 %
IP = IPR(max); TA = –40°C to 25°C –2 ±1.5 2 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
IP = IPR(max); TA = 25°C to 150°C –1.5 ±0.7 1.5 %
IP = IPR(max); TA = –40°C to 25°C –1.5 ±1 1.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –10 ±3 10 mV
IP = 0 A; TA = –40°C to 25°C –10 ±6 10 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
xLLCTR-30AU PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
NOMINAL PERFORMANCE
Current Sensing Range IPR 0 – 30 A
Sensitivity Sens IPR(min) < IP < IPR(max) 88 – mV/A
Zero Current Output Voltage VIOUT(Q) Unidirectional; IP = 0 A VCC ×
0.1 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2 ±0.8 2 %
IP = IPR(max); TA = –40°C to 25°C –6 ±4 6 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
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 5.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –10 ±4 10 mV
IP = 0 A; TA = –40°C to 25°C –30 ±5 30 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
10
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-40AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
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 ×
0.5 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2 ±1 2 %
IP = IPR(max); TA = –40°C to 25°C –6 ±4 6 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
IP = IPR(max); TA = 25°C to 150°C –1.5 ±1 1.5 %
IP = IPR(max); TA = –40°C to 25°C –5.5 ±4 5.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –10 ±3 10 mV
IP = 0 A; TA = –40°C to 25°C –30 ±5 30 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
xLLCTR-50AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 3.3 V, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. [1] Max. Unit
NOMINAL PERFORMANCE
Current 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 VCC ×
0.5 – V
ACCURACY PERFORMANCE
Total Output Error [2] ETOT
IP = IPR(max); TA = 25°C to 150°C –2 ±1 2 %
IP = IPR(max); TA = –40°C to 25°C –6 ±4 6 %
TOTAL OUTPUT ERROR COMPONENTS [3] ETOT = ESENS + 100 x VOE/(Sens x IP)
Sensitivity Error Esens
IP = IPR(max); TA = 25°C to 150°C –1.5 ±1 1.5 %
IP = IPR(max); TA = –40°C to 25°C –5.5 ±4 5.5 %
Offset Voltage VOE
IP = 0 A; TA = 25°C to 150°C –10 ±3 10 mV
IP = 0 A; TA = –40°C to 25°C –30 ±5 30 mV
LIFETIME DRIFT CHARACTERISTICS
Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 %
Total Output Error Lifetime
Drift Etot_drift –3 ±1 3 %
[1] Typical values with ± are 3 sigma values
[2] Percentage of IP
, with IP = IPR(max).
[3] A single part 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. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section.
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
11
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
CHARACTERISTIC PERFORMANCE
xLLCTR-10AU
340
350
335
345
330
325
320
315
310
-50 050 100 150
Temperature (ºC)
V (mV)
IOUT(Q)
Zero Current Output Voltage vs. Temperature
-15
-20
-10
-5
0
5
10
15
20
-50 050 100 150
Temperature (ºC)
Offset Voltage (mV)
Offset Voltage vs. Temperature
268
266
264
262
260
256
254
252
250
-50 050 100 150
Temperature (ºC)
Sensitivity (mV/A)
Sensitivity vs. Temperature
258
1
0
-1
-2
-3
-4
-5
-50 050 100 150
Temperature (ºC)
Sensitivity Error (%)
Sensitivity Error vs. Temperature
1.00
0.80
0.60
0.40
0.20
0.00
-0.20
-0.60
-0.40
-0.80
-1.00
-50 050 100 150
Temperature (ºC)
Nonlinearity (%)
Nonlinearity vs. Temperature
2
1
0
-1
-2
-4
-3
-5
-6
-50 050 100 150
Temperature (ºC)
Total Error (%)
Total Error at I vs. Temperature
PR(max)
+3 Sigma -3 Sigma
Average
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
12
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-20AU
320
322
324
326
328
330
332
334
336
-500 50 10
01
50
VIOUT(Q)(mV)
Temperature (°C)
Zero Current Output Voltage vs. Temperature
+3 Sigma -3 Sigma
Average
127
128
129
130
131
132
133
134
-500 50 10
01
50
Sensivity (mV/A)
Temperature (°C)
Sensivity vs. Temperature
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
-500 50 10
01
50
Nonlinearity (%)
Temperature (°C)
Nonlinearity vs. Temperature
-10.00
-8.00
-6.00
-4.00
-2.00
0.00
2.00
4.00
6.00
-500 50 10
01
50
Offset Voltage (mV)
Temperature (°C)
Offset Voltage vs. Temperature
-4
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
-500 50 10
01
50
Sensivity Error (%)
Temperature (°C)
Sensivity Error vs. Temperature
-4
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
-500 50 10
50
Total Error (%)
Temperature (°C)
Total Error at IPR(max)vs. Temperature
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
13
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-20AB
1654
1656
1653
1655
1652
1648
1647
1646
1645
-50 050 100 150
Temperature (ºC)
V (mV)
IOUT(Q)
Zero Current Output Voltage vs. Temperature
1651
1650
1649
-50 050 100 150
Temperature (ºC)
Offset Voltage (mV)
Offset Voltage vs. Temperature
4
6
3
5
2
-2
-3
-4
-5
1
0
-1
67
66
66
65
64
64
63
-50 050 100 150
Temperature (ºC)
Sensitivity (mV/A)
Sensitivity vs. Temperature
65
1
0
-1
-2
-3
-4
-5
-50 050 100 150
Temperature (ºC)
Sensitivity Error (%)
Sensitivity Error vs. Temperature
1.00
0.80
0.60
0.40
0.20
0.00
-0.20
-0.60
-0.40
-0.80
-1.00
-50 050 100 150
Temperature (ºC)
Nonlinearity (%)
Nonlinearity vs. Temperature
1
0
-1
-2
-4
-3
-5
-50 050 100 150
Temperature (ºC)
Total Error (%)
Total Error at I vs. Temperature
PR(max)
+3 Sigma -3 Sigma
Average
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
14
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-30AB
1654
1656
1652
1646
1644
-50 050 100 150
Temperature (ºC)
V (mV)
IOUT(Q)
Zero Current Output Voltage vs. Temperature
1650
1648
-50 050 100 150
Temperature (ºC)
Offset Voltage (mV)
Offset Voltage vs. Temperature
4
6
2
-4
-6
0
-2
45
44
44
43
43
42
42
-50 050 100 150
Temperature (ºC)
Sensitivity (mV/A)
Sensitivity vs. Temperature
1
0
-1
-2
-3
-4
-5
-50 050 100 150
Temperature (ºC)
Sensitivity Error (%)
Sensitivity Error vs. Temperature
1.00
0.80
0.60
0.40
0.20
0.00
-0.20
-0.60
-0.40
-0.80
-1.00
-50 050 100 150
Temperature (ºC)
Nonlinearity (%)
Nonlinearity vs. Temperature
1
0
-1
-2
-4
-3
-5
-50 050 100 150
Temperature (ºC)
Total Error (%)
Total Error at I vs. Temperature
PR(max)
+3 Sigma -3 Sigma
Average
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
15
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-30AB-H
+3 Sigma -3 Sigma
Average
1646
1648
1650
1652
1654
1656
1658
-50 050 100 150
V
IOUT(Q)
(mV)
Temperature (°C)
Zero Current Output Voltage vs. Temperature
42
43
44
45
46
-50 050 100 150
Sensitivity (mV/A)
Temperature (°C)
Sensitivity vs. Temperature
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
-50 050 100 150
Nonlinearity (%)
Temperature (°C)
Nonlinearity vs. Temperature
-3
-2
-1
0
1
2
3
-50 050 100 150
Total Error (%)
Temperature (°C)
Total Error at I
PR(max)
vs. Temperature
-8.00
-6.00
-4.00
-2.00
0.00
2.00
4.00
6.00
8.00
-50 050 100 150
Offset Voltage (mV)
Temperature (°C)
Offset Voltage vs. Temperature
-3
-2
-1
0
1
2
3
-50 050 100 150
Sensitivity Error (%)
Temperature (°C)
Sensitivity Error vs. Temperature
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
16
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
xLLCTR-40AB
1654
1656
1652
1646
1644
-50 050 100 150
Temperature (ºC)
V (mV)
IOUT(Q)
Zero Current Output Voltage vs. Temperature
1650
1648
-50 050 100 150
Temperature (ºC)
Offset Voltage (mV)
Offset Voltage vs. Temperature
4
6
2
-4
-6
0
-2
33
32
32
32
32
32
31
-50 050 100 150
Temperature (ºC)
Sensitivity (mV/A)
Sensitivity vs. Temperature
33
33
33
33
1
0
-1
-2
-3
-4
-5
-50 050 100 150
Temperature (ºC)
Sensitivity Error (%)
Sensitivity Error vs. Temperature
2
1.00
0.80
0.60
0.40
0.20
0.00
-0.20
-0.60
-0.40
-0.80
-1.00
-50 050 100 150
Temperature (ºC)
Nonlinearity (%)
Nonlinearity vs. Temperature
1
0
-1
-2
-4
-3
-5
-50 050 100 150
Temperature (ºC)
Total Error (%)
Total Error at I vs. Temperature
PR(max)
2
+3 Sigma -3 Sigma
Average
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
17
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
CHARACTERISTIC PERFORMANCE
ACS724 TYPICAL FREQUENCY RESPONSE
10
1
10
2
10
3
10
4
10
5
Frequency [Hz]
-10
-5
0
5
Magnitude [dB]
ACS724 Frequency Response
10
1
10
2
10
3
10
4
10
5
Frequency [Hz]
-150
-100
-50
0
50
Phase [°]
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
18
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
APPLICATION INFORMATION
Estimating Total Error vs. Sensed Current
The Performance Characteristics tables give distribution (±3
sigma) values for Total Error at IPR(max); however, one often
wants to know what error to expect at a particular current. This
can be estimated by using the distribution data for the compo-
nents of Total Error, Sensitivity Error, and Offset Voltage. The
±3 sigma value for Total Error (ETOT) as a function of the sensed
current (IP) is estimated as:
E(I) =
TOTP E+
SENS
2100 × VOE
2
Sens × IP
()
Here, ESENS and VOE are the ±3 sigma values for those error
terms. If there is an average sensitivity error or average offset
voltage, then the average Total Error is estimated as:
E(I) = E+
TOTP SENS
100 × VOE
Sens × IP
AVGAVG
AVG
The resulting total error will be a sum of ETOT and ETOT_AVG.
Using these equations and the 3 sigma distributions for Sensitiv-
ity Error and Offset Voltage, the Total Error vs. sensed current
(IP) is below for the ACS725LLCTR-20AB. As expected, as one
goes towards zero current, the error in percent goes towards infin-
ity due to division by zero.
8
6
4
2
0
-2
-4
-6
-8
0510 15 20
-40ºC + 3σ
-40ºC –3σ
25ºC + 3σ
25ºC –3σ
85ºC + 3σ
85ºC –3σ
Current (A)
Total Error (% of Current Measured)
Figure 1: Predicted Total Error as a Function of the Sensed Current for the ACS725LLCTR-20AB
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
19
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Thermal Rise vs. Primary Current
Self-heating due to the flow-off current should be considered dur-
ing 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 cur-
rent. The current profile includes peak current, current “on-time”,
and duty cycle. While the data presented in this section was
collected with direct current (DC), these numbers may be used
to approximate thermal response for both AC signals and current
pulses.
The plot in Figure 2 shows the measured rise in steady-state die
temperature of the ACS725 versus DC input current at an ambi-
ent temperature, TA, of 25 °C. The thermal offset curves may be
directly applied to other values of TA.
Figure 2: Self Heating in the LA Package
Due to Current Flow
The thermal capacity of the ACS725 should be verified by the
end user in the application’s specific conditions. The maximum
junction temperature, TJ(MAX) (165°C), 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.
ASEK724/5 Evaluation Board Layout
Thermal data shown in Figure 2 was collected using the
ASEK724/5 Evaluation Board (TED-85-0740-003). This board
includes 1500 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 below in
Figure 3.
Figure 3: Top and Bottom Layers
for ASEK724/5 Evaluation Board
Gerber files for the ASEK724/5 evaluation board are available for
download from our website. See the technical documents section
of the ACS725 device webpage.
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
20
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 ampli-
fier 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:
E=
LIN
1–
V(I)–V
IOUT PR(max) IOUT(Q)
2V(I /2) –V
IOUT PR(max) IOUT(Q)
• 100(%)
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 volt-
age to amperes, divide by the device sensitivity, Sens.
Total Output Error (ETOT). The difference between the cur-
rent 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(I)
TOTP
V(I)–V (I )
IOUT_ideal PIOUT P
Sens (I )•I
ideal PP
100 (%)
=
The Total Output Error incorporates all sources of error and is a
function 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
4 and Figure 5. Figure 4 shows a distribution of output voltages
versus IP at 25°C and across temperature. Figure 5 shows the cor-
responding ETOT versus IP .
DEFINITIONS OF ACCURACY CHARACTERISTICS
Figure 4: Output Voltage versus Sensed Current
Figure 5: Total Output Error versus Sensed Current
0 A
Decreasing
V
IOUT
(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
V
IOUT
(V)
Ideal V
IOUT
I
PR
(min)
I
PR
(max)
+I
P
(A)
–I
P
(A)
V
IOUT(Q)
Full Scale I
P
+I
P
–I
P
+E
TOT
–E
TOT
Across Temperature
25°C Only
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
21
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Sensitivity Ratiometry Coefficient (SENS_RAT_COEF). The
coefficient defining how the sensitivity scales with VCC. The
ideal coefficient is 1, meaning the sensitivity scales proportion-
ally with VCC. A 10% increase in VCC results in a 10% increase
in sensitivity. A coefficient of 1.1 means that the sensitivity
increases by 10% more than the ideal proportionality case. This
means that a 10% increase in VCC results in an 11% increase in
sensitivity. This relationship is described by the following equa-
tion:
Sens(V ) = Sens(3.3 V)
CC
(V – 3.3 V) • SENS_RAT_COEF
CC
3.3 V
1 +
This can be rearranged to define the sensitivity ratiometry coef-
ficient as:
Sens(3.3 V) (V – 3.3 V)
CC
SENS_RAT_COEF = Sens(V )
CC 3.3 V
–1
Zero Current Output Ratiometry Coefficient (QVO_RAT_
COEF). The coefficient defining how the zero current output
voltage scales with VCC. The ideal coefficient is 1, meaning the
output voltage scales proportionally with VCC, always being
equal to VCC/2. A coefficient of 1.1 means that the zero current
output voltage increases by 10% more than the ideal proportion-
ality case. This means that a 10% increase in VCC results in an
11% increase in the zero current output voltage. This relationship
is described by the following equation:
VIOUTQ(V ) = VIOUTQ(3.3 V)
CC
(V – 3.3 V) •QVO_RAT_COEF
CC
3.3 V
1 +
This can be rearranged to define the zero current output ratiom-
etry coefficient as:
VIOUTQ(3.3 V) (V – 3.3 V)
CC
QVO_RAT_COEF = VIOUTQ(V )
CC 3.3 V
–1
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
22
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 operat-
ing 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 bandwidth 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.
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.
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.
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 6: Power-On Time (tPO)
Figure 7: Rise Time (tr) and Propagation Delay (tpd)
Figure 8: Response Time (tRESPONSE)
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
23
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Figure 9: Package LC, 8-Pin SOICN
For Reference Only Not for Tooling Use
(Reference MS-012AA)
Dimensions in millimeters–NOTTO SCALE
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
C
SEATING
PLANE
1.27 BSC
C
C0.10
8X
1.75 MAX
0.51
0.31 0.25
0.10
Branded Face
A
B
C
Branding scale and appearance at supplier discretion
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.
21
8
4.90 ±0.10
3.90 ±0.10 6.00 ±0.20
A
0.25 BSC
1.04 REF
0.25
0.17
1.27
0.40
SEATING PLANE
GAUGE PLANE
21
8
C
0.65 1.27
5.60
1.75
PCB Layout Reference View 1
1.27 7.35
Package Outline
Slot in PCB to maintain
4.2 mm creepage once
part is on PCB
21
8
C
0.65 1.27
4.20
1.575
PCB Layout Reference View 2
7.35
For PCB assemblies that cannot support a slotted design,
the above stretched footprint may be used.
BStandard Branding Reference View
1
N = Device part number
P= Package Designator
T= Device temperature range
A=Amperage
L= Lot number
Belly Brand = Country of Origin
NNNNNNN
PPT-AAA
LLLLL
PACKAGE OUTLING DRAWING
Automotive-Grade, Galvanically Isolated Current Sensor IC
With Common-Mode Field Rejection in a Small Footprint SOIC8 Package
ACS725
24
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
Number Change Pages Responsible Date
Initial Release All A. Latham January 19, 2015
1
Added ACS725LLCTR-20AU-T to Selection Guide and Performance
Characteristics charts, and corrected Sensitivity Error;
added xLLCTR-20AU Characteristic Performance charts.
2, 6-8,
10 A. Latham September 28, 2015
2Added ACS725LLCTR-30AU-T to Selection Guide and Performance
Characteristics charts. 2, 8 A. Latham December 11, 2015
3Added ACS725LLCTR-50AB-T to Selection Guide and Performance
Characteristics charts. 2, 9 W. Bussing March 17, 2017
4Added AEC-Q100 qualified status 1 W. Bussing June 28, 2017
5Added ACS725LLCTR-05AB-T and ACS725LLCTR-10AB-T to Selection Guide
and Performance Characteristics charts. 2, 5 M. McNally November 15, 2017
6 Updated Clearance and Creepage rating values 3 W. Bussing January 10, 2018
7Added Dielectric Surge Strength Test Voltage characteristic 2 W. Bussing January 23, 2018
Added Common Mode Field Rejection Ratio characteristic 5
8 Updated PCB Layout References in Package Outline Drawing 20 W. Bussing March 19, 2018
9Added Typical Frequency Response plots 16 W. Bussing June 22, 2018
10 Added “Thermal Rise vs. Primary Current” and “ASEK724/5 Evaluation Board
Layout” to the Applications Information section 18 W. Bussing July 3, 2018
11 Added ACS725LLCTR-30AB-T-H to Selection Guide and Performance
Characteristic Charts. 2, 9, 15 M. McNally July 30, 2018
12 Updated certificate numbers 1 V. Mach December 13, 2018
Copyright ©2018, Allegro MicroSystems, LLC
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
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 of
Allegro’s product can reasonably be expected to cause bodily harm.
The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, LLC 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.

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