ACS712
Fully Integrated, Hall Effect-Based Linear Current Sensor
with 2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor
Features and Benefits
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Low-noise analog signal path
Device bandwidth is set via the new FILTER pin
5
μs
output rise time in response to step input current
80 kHz bandwidth
Total output error 1.5% at T
A
= 25°C
Small footprint, low-profile SOIC8 package
1.2 mΩ internal conductor resistance
2.1 kV
RMS
minimum isolation voltage from pins 1-4 to pins 5-8
5.0 V, single supply operation
66 to 185 mV/A output sensitivity
Output voltage proportional to AC or DC currents
Factory-trimmed for accuracy
Extremely stable output offset voltage
Nearly zero magnetic hysteresis
Ratiometric output from supply voltage
TÜV America
Certificate Number:
U8V 06 05 54214 010
Description
The Allegro
®
ACS712 provides economical and precise
solutions for AC or DC current sensing in industrial,
commercial, and communications systems. The device
package allows for easy implementation by the customer.
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 signal 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 (>V
IOUT(Q)
)
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
Continued on the next page…
Package: 8 Lead SOIC (suffix LC)
Approximate Scale 1:1
Typical Application
+5 V
1
2
I
P
3
4
IP+
VCC
8
7
V
OUT
C
BYP
0.1 μF
IP+ VIOUT
ACS712
IP– FILTER
IP–
GND
6
5
C
F
1 nF
Application 1. The ACS712 outputs an analog signal, V
OUT
.
that varies linearly with the uni- or bi-directional AC or DC
primary sensed current, I
P
, within the range specified. C
F
is recommended for noise management, with values that
depend on the application.
ACS712-DS, Rev. 7
ACS712
Fully Integrated, Hall Effect-Based Linear Current Sensor with
2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor
Description (continued)
loss. The thickness of the copper conductor allows survival of
the device at up to 5× overcurrent conditions. The terminals of
the conductive path are electrically isolated from the sensor leads
(pins 5 through 8). This allows the ACS712 current sensor to be
used in applications requiring electrical isolation without the use
of opto-isolators or other costly isolation techniques.
Selection Guide
Part Number
ACS712ELCTR-05B-T
ACS712ELCTR-20A-T
ACS712ELCTR-30A-T
Packing*
Tape and reel, 3000 pieces/reel
Tape and reel, 3000 pieces/reel
Tape and reel, 3000 pieces/reel
The ACS712 is provided in a small, 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.
T
A
(°C)
–40 to 85
–40 to 85
–40 to 85
Optimized Range, I
P
(A)
±5
±20
±30
Sensitivity, Sens
(Typ) (mV/A)
185
100
66
*Contact Allegro for additional packing options.
Absolute Maximum Ratings
Characteristic
Supply Voltage
Reverse Supply Voltage
Output Voltage
Reverse Output Voltage
Reinforced Isolation Voltage
Symbol
V
CC
V
RCC
V
IOUT
V
RIOUT
Pins 1-4 and 5-8; 60 Hz, 1 minute, T
A
=25°C
V
ISO
Voltage applied to leadframe (Ip+ pins), based
on IEC 60950
Pins 1-4 and 5-8; 60 Hz, 1 minute, T
A
=25°C
Basic Isolation Voltage
Output Current Source
Output Current Sink
Overcurrent Transient Tolerance
Nominal Operating Ambient Temperature
Maximum Junction Temperature
Storage Temperature
V
ISO(bsc)
I
IOUT(Source)
I
IOUT(Sink)
I
P
T
A
T
J
(max)
T
stg
1 pulse, 100 ms
Range E
Voltage applied to leadframe (Ip+ pins), based
on IEC 60950
Notes
Rating
8
–0.1
8
–0.1
2100
184
1500
354
3
10
100
–40 to 85
165
–65 to 170
Units
V
V
V
V
V
V
peak
V
V
peak
mA
mA
A
ºC
ºC
ºC
Parameter
Fire and Electric Shock
Specification
CAN/CSA-C22.2 No. 60950-1-03
UL 60950-1:2003
EN 60950-1:2001
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
2
ACS712
Fully Integrated, Hall Effect-Based Linear Current Sensor with
2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor
Functional Block Diagram
+5 V
VCC
(Pin 8)
Hall Current
Drive
IP+
(Pin 1)
Sense Temperature
Coefficient Trim
Dynamic Offset
Cancellation
IP+
(Pin 2)
Signal
Recovery
R
F(INT)
VIOUT
(Pin 7)
IP−
(Pin 3)
IP−
(Pin 4)
Sense
Trim
0 Ampere
Offset Adjust
GND
(Pin 5)
FILTER
(Pin 6)
Pin-out Diagram
IP+
IP+
IP–
IP–
1
2
3
4
8
7
6
5
VCC
VIOUT
FILTER
GND
Terminal List Table
Number
1 and 2
3 and 4
5
6
7
8
Name
IP+
IP–
GND
FILTER
VIOUT
VCC
Description
Terminals for current being sensed; fused internally
Terminals for current being sensed; fused internally
Signal ground terminal
Terminal for external capacitor that sets bandwidth
Analog output signal
Device power supply terminal
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
3
ACS712
Fully Integrated, Hall Effect-Based Linear Current Sensor with
2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor
COMMON OPERATING CHARACTERISTICS
1
over full range of T
A
, C
F
= 1 nF, and V
CC
= 5 V, unless otherwise specified
Characteristic
Supply Voltage
Supply Current
Output Capacitance Load
Output Resistive Load
Primary Conductor Resistance
Rise Time
Frequency Bandwidth
Nonlinearity
Symmetry
Zero Current Output Voltage
Power-On Time
Magnetic Coupling
2
Internal Filter Resistance
3
1
Device
Symbol
V
CC
I
CC
C
LOAD
R
LOAD
R
PRIMARY
t
r
f
E
LIN
E
SYM
V
IOUT(Q)
t
PO
R
F(INT)
Test Conditions
Min.
4.5
Typ.
5.0
10
–
–
1.2
5
80
1.5
100
V
CC
×
0.5
35
12
1.7
Max.
5.5
13
10
–
–
–
–
–
102
–
–
–
Units
V
mA
nF
kΩ
mΩ
μs
kHz
%
%
V
μs
G/A
kΩ
ELECTRICAL CHARACTERISTICS
V
CC
= 5.0 V, output open
VIOUT to GND
VIOUT to GND
T
A
= 25°C
I
P
= I
P
(max), T
A
= 25°C, C
OUT
= open
–3 dB, T
A
= 25°C; I
P
is 10 A peak-to-peak
Over full range of I
P
Over full range of I
P
Bidirectional; I
P
= 0 A, T
A
= 25°C
Output reaches 90% of steady-state level, T
J
= 25°C, 20 A present
on leadframe
–
–
4.7
–
–
–
–
98
–
–
–
may be operated at higher primary current levels, I
P
, and ambient, T
A
, and internal leadframe temperatures, T
A
, provided that the Maximum
Junction Temperature, T
J
(max), is not exceeded.
2
1G = 0.1 mT.
3
R
F(INT)
forms an RC circuit via the FILTER pin.
COMMON THERMAL CHARACTERISTICS
1
Min.
Operating Internal Leadframe Temperature
Junction-to-Lead Thermal
Resistance
2
T
A
R
θJL
R
θJA
E range
Mounted on the Allegro ASEK 712 evaluation board
Mounted on the Allegro 85-0322 evaluation board, includes the power con-
sumed by the board
–40
Typ.
–
Max.
85
Value
5
23
Units
°C
Units
°C/W
°C/W
Junction-to-Ambient Thermal Resistance
1
Additional
2
The Allegro
thermal information is available on the Allegro website.
evaluation board has 1500 mm
2
of 2 oz. copper on each side, connected to pins 1 and 2, and to pins 3 and 4, with thermal vias connect-
ing the layers. Performance values include the power consumed by the PCB. Further details on the board are available from the Frequently Asked
Questions document on our website. Further information about board design and thermal performance also can be found in the Applications Informa-
tion section of this datasheet.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
4
ACS712
Fully Integrated, Hall Effect-Based Linear Current Sensor with
2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor
x05B PERFORMANCE CHARACTERISTICS
T
A
= –40°C to 85°C
1
, C
F
= 1 nF, and V
CC
= 5 V, unless otherwise specified
Characteristic
Optimized Accuracy Range
Sensitivity
Noise
Zero Current Output Slope
Sensitivity Slope
Total Output
1
Device
Symbol
I
P
Sens
V
NOISE(PP)
∆I
OUT(Q)
∆Sens
E
TOT
Test Conditions
Over full range of I
P,
T
A
= 25°C
Peak-to-peak, T
A
= 25°C, 185 mV/A programmed Sensitivity,
C
F
= 47 nF, C
OUT
= open, 2 kHz bandwidth
T
A
= –40°C to 25°C
T
A
= 25°C to 150°C
T
A
= –40°C to 25°C
T
A
= 25°C to 150°C
I
P
=±5 A, T
A
= 25°C
Min.
–5
180
–
–
–
–
–
–
Typ.
–
185
21
–0.26
–0.08
0.054
–0.008
±1.5
Max.
5
190
–
–
–
–
–
–
Units
A
mV/A
mV
mV/°C
mV/°C
mV/A/°C
mV/A/°C
%
Error
2
may be operated at higher primary current levels, I
P
, and ambient temperatures, T
A
, provided that the Maximum Junction Temperature, T
J(max)
,
is not exceeded.
2
Percentage of I , with I = 5 A. Output filtered.
P
P
x20A PERFORMANCE CHARACTERISTICS
T
A
= –40°C to 85°C
1
, C
F
= 1 nF, and V
CC
= 5 V, unless otherwise specified
Characteristic
Optimized Accuracy Range
Sensitivity
Noise
Zero Current Output Slope
Sensitivity Slope
Total Output
1
Device
Symbol
I
P
Sens
V
NOISE(PP)
∆I
OUT(Q)
∆Sens
E
TOT
Test Conditions
Over full range of I
P,
T
A
= 25°C
Peak-to-peak, T
A
= 25°C, 100 mV/A programmed Sensitivity,
C
F
= 47 nF, C
OUT
= open, 2 kHz bandwidth
T
A
= –40°C to 25°C
T
A
= 25°C to 150°C
T
A
= –40°C to 25°C
T
A
= 25°C to 150°C
I
P
=±20 A, T
A
= 25°C
Min.
–20
96
–
–
–
–
–
–
Typ.
–
100
11
–0.34
–0.07
0.017
–0.004
±1.5
Max.
20
104
–
–
–
–
–
–
Units
A
mV/A
mV
mV/°C
mV/°C
mV/A/°C
mV/A/°C
%
Error
2
may be operated at higher primary current levels, I
P
, and ambient temperatures, T
A
, provided that the Maximum Junction Temperature,
T
J
(max), is not exceeded.
2
Percentage of I , with I = 20 A. Output filtered.
P
P
x30A PERFORMANCE CHARACTERISTICS
T
A
= –40°C to 85°C
1
, C
F
= 1 nF, and V
CC
= 5 V, unless otherwise specified
Characteristic
Optimized Accuracy Range
Sensitivity
Noise
Zero Current Output Slope
Sensitivity Slope
Total Output
1
Device
Symbol
I
P
Sens
V
NOISE(PP)
∆I
OUT(Q)
∆Sens
E
TOT
Test Conditions
Over full range of I
P
, T
A
= 25°C
Peak-to-peak, T
A
= 25°C, 66 mV/A programmed Sensitivity,
C
F
= 47 nF, C
OUT
= open, 2 kHz bandwidth
T
A
= –40°C to 25°C
T
A
= 25°C to 150°C
T
A
= –40°C to 25°C
T
A
= 25°C to 150°C
I
P
= ±30 A , T
A
= 25°C
Min.
–30
64
–
–
–
–
–
–
Typ.
–
66
7
–0.35
–0.08
0.007
–0.002
±1.5
Max.
30
68
–
–
–
–
–
–
Units
A
mV/A
mV
mV/°C
mV/°C
mV/A/°C
mV/A/°C
%
Error
2
may be operated at higher primary current levels, I
P
, and ambient temperatures, T
A
, provided that the Maximum Junction Temperature,
T
J
(max), is not exceeded.
2
Percentage of I , with I = 30 A. Output filtered.
P
P
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
5
嵌入式系统
