ACS713 Datasheet

ACS713
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
Features and Benefits
Description
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The Allegro™ ACS713 provides economical and precise
solutions for 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, switch-mode
power supplies, and overcurrent fault protection. The device
is not intended for automotive applications.
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 TA = 25°C
Small footprint, low-profile SOIC8 package
1.2 mΩ internal conductor resistance
2.1 kVRMS minimum isolation voltage from pins 1-4 to pins 5-8
5.0 V, single supply operation
133 to 185 mV/A output sensitivity
Output voltage proportional to DC currents
Factory-trimmed for accuracy
Extremely stable output offset voltage
Nearly zero magnetic hysteresis
Ratiometric output from supply voltage
The device consists of a precise, low-offset, linear Hall 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 the Hall IC converts 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 (>VIOUT(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 sampling. The internal resistance of
this conductive path is 1.2 mΩ typical, providing low power
loss. The thickness of the copper conductor allows survival of
TÜV America
Certificate Number:
U8V 06 05 54214 010
Package: 8 Lead SOIC (suffix LC)
Continued on the next page…
Approximate Scale 1:1
Typical Application
+5 V
1
2
IP
IP+
VCC
IP+ VIOUT
8
7
VOUT
CBYP
0.1 μF
ACS713
3
4
IP– FILTER
IP–
GND
6
5
CF
Application 1. The ACS713 outputs an analog signal, VOUT .
that varies linearly with the unidirectional DC primary sampled
current, IP , within the range specified. CF is recommended for
noise management, with values that depend on the application.
ACS713-DS, Rev. 12
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
Description (continued)
the device at up to 5× overcurrent conditions. The terminals of the
conductive path are electrically isolated from the signal leads (pins
5 through 8). This allows the ACS713 to be used in applications
requiring electrical isolation without the use of opto-isolators or
other costly isolation techniques.
The ACS713 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.
Selection Guide
Part Number
Packing*
TA
(°C)
Optimized Range, IP
(A)
Sensitivity, Sens
(Typ) (mV/A)
ACS713ELCTR-20A-T
Tape and reel, 3000 pieces/reel
–40 to 85
0 to 20
185
ACS713ELCTR-30A-T
Tape and reel, 3000 pieces/reel
–40 to 85
0 to 30
133
*Contact Allegro for additional packing options.
Absolute Maximum Ratings
Characteristic
Symbol
Notes
Rating
Units
Supply Voltage
VCC
8
V
Reverse Supply Voltage
VRCC
–0.1
V
Output Voltage
VIOUT
8
V
Reverse Output Voltage
VRIOUT
–0.1
V
Pins 1-4 and 5-8; 60 Hz, 1 minute, TA=25°C
2100
VAC
VISO
Maximum working voltage according to
UL60950-1
184
Vpeak
Pins 1-4 and 5-8; 60 Hz, 1 minute, TA=25°C
1500
VAC
Basic Isolation Voltage
VISO(bsc)
Maximum working voltage according to
UL60950-1
354
Vpeak
Output Current Source
IOUT(Source)
3
mA
10
mA
Reinforced Isolation Voltage
Output Current Sink
IOUT(Sink)
Overcurrent Transient Tolerance
IP
1 pulse, 100 ms
Nominal Operating Ambient Temperature
TA
Range E
Maximum Junction Temperature
Storage Temperature
100
A
–40 to 85
ºC
TJ(max)
165
ºC
Tstg
–65 to 170
ºC
Isolation Characteristics
Characteristic
Symbol
Notes
Rating
Unit
2100
VAC
Dielectric Strength Test Voltage*
VISO
Agency type-tested for 60 seconds per
UL standard 60950-1, 1st Edition
Working Voltage for Basic Isolation
VWFSI
For basic (single) isolation per UL standard
60950-1, 1st Edition
354
VDC or Vpk
Working Voltage for Reinforced Isolation
VWFRI
For reinforced (double) isolation per UL standard
60950-1, 1st Edition
184
VDC or Vpk
* Allegro does not conduct 60-second testing. It is done only during the UL certification process.
Parameter
Specification
Fire and Electric Shock
CAN/CSA-C22.2 No. 60950-1-03
UL 60950-1:2003; EN 60950-1:2001
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
2
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
Functional Block Diagram
+5 V
VCC
(Pin 8)
Hall Current
Drive
IP+
(Pin 1)
Sense Temperature
Coefficient Trim
Dynamic Offset
Cancellation
IP+
(Pin 2)
IP–
(Pin 3)
Signal
Recovery
VIOUT
(Pin 7)
Sense
Trim
IP–
(Pin 4)
0 Ampere
Offset Adjust
GND
(Pin 5)
FILTER
(Pin 6)
Pin-out Diagram
IP+
1
8
VCC
IP+
2
7
VIOUT
IP–
3
6
FILTER
IP–
4
5
GND
Terminal List Table
Number
Name
1 and 2
IP+
Input terminals for current being sampled; fused internally
Description
3 and 4
IP–
Output terminals for current being sampled; fused internally
5
GND
6
FILTER
Terminal for external capacitor that sets bandwidth
7
VIOUT
Analog output signal
8
VCC
Signal ground terminal
Device power supply terminal
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
3
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
COMMON OPERATING CHARACTERISTICS1 over full range of TA, and VCC = 5 V, unless otherwise specified
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
4.5
5.0
5.5
V
–
10
13
mA
ELECTRICAL CHARACTERISTICS
Supply Voltage
VCC
Supply Current
ICC
VCC = 5.0 V, output open
Output Capacitance Load
CLOAD
VIOUT to GND
–
–
10
nF
Output Resistive Load
RLOAD
VIOUT to GND
4.7
–
–
kΩ
Primary Conductor Resistance
Rise Time
Frequency Bandwidth
Nonlinearity
Zero Current Output Voltage
Power-On Time
RPRIMARY
TA = 25°C
–
1.2
–
mΩ
tr
IP = IP(max), TA = 25°C, COUT = 10 nF
–
3.5
–
μs
f
–3 dB, TA = 25°C; IP is 10 A peak-to-peak
–
80
–
kHz
Over full range of IP , IP applied for 5 ms
–
±1.5
–
%
Unidirectional; IP = 0 A, TA = 25°C
–
VCC ×
0.1
–
V
Output reaches 90% of steady-state level, no capacitor on
FILTER pin; TJ = 25; 20 A present on leadframe
–
35
–
μs
12
–
G/A
ELIN
VIOUT(Q)
tPO
Magnetic Coupling2
Internal Filter Resistance3
–
RF(INT)
1.7
kΩ
1Device
may be operated at higher primary current levels, IP, and ambient, TA , and internal leadframe temperatures, TA , provided that the Maximum
Junction Temperature, TJ(max), is not exceeded.
21G = 0.1 mT.
3R
F(INT) forms an RC circuit via the FILTER pin.
COMMON THERMAL CHARACTERISTICS1
Operating Internal Leadframe Temperature
TA
E range
Min.
Typ.
Max.
Units
–40
–
85
°C
Value
Units
Junction-to-Lead Thermal Resistance2
RθJL
Mounted on the Allegro ASEK 713 evaluation board
5
°C/W
Junction-to-Ambient Thermal Resistance2,3
RθJA
Mounted on the Allegro 85-0322 evaluation board, includes the power
consumed by the board
23
°C/W
1Additional
thermal information is available on the Allegro website.
evaluation board has 1500 mm2 of 2 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. 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 Information section of this datasheet.
3R
θJA values shown in this table are typical values, measured on the Allegro evaluation board. The actual thermal performance depends on the actual
application board design, the airflow in the application, and thermal interactions between the device and surrounding components through the PCB and
the ambient air. To improve thermal performance, see our applications material on the Allegro website.
2The Allegro
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
4
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
x20A PERFORMANCE CHARACTERISTICS TA = –40°C to 85°C1; VCC = 5 V, unless otherwise specified
Characteristic
Optimized Accuracy Range
Sensitivity
Symbol
Test Conditions
IP
Sens
Over full range of IP, TA = 25°C
Noise
Peak-to-peak, TA = 25°C, 2 kHz external filter, 185 mV/A
VNOISE(PP) programmed Sensitivity, CF = 47 nF, COUT = 10 nF, 2 kHz
bandwidth
Zero Current Output Slope
∆VOUT(Q)
Sensitivity Slope
Total Output Error2
∆Sens
ETOT
Min.
Typ.
Max.
0
–
20
Units
A
178
185
190
mV/A
–
21
–
mV
mV/°C
TA = –40°C to 25°C
–
0.08
–
TA = 25°C to 150°C
–
0.16
–
mV/°C
TA = –40°C to 25°C
–
0.035
–
mV/A/°C
TA = 25°C to 150°C
–
0.019
–
mV/A/°C
IP = 20 A , IP applied for 5 ms; TA = 25°C
–
±1.5
–
%
1Device
may be operated at higher primary current levels, IP, and ambient temperatures, TA, provided that the Maximum Junction Temperature,
TJ(max), is not exceeded.
2Percentage of I , with I = 20 A. Output filtered.
P
P
x30A PERFORMANCE CHARACTERISTICS TA = –40°C to 85°C1; VCC = 5 V, unless otherwise specified
Characteristic
Optimized Accuracy Range
Sensitivity
Symbol
Test Conditions
IP
Sens
Over full range of IP, TA = 25°C
Noise
Peak-to-peak, TA = 25°C, 2 kHz external filter, 133 mV/A
VNOISE(PP) programmed Sensitivity, CF = 47 nF, COUT = 10 nF, 2 kHz
bandwidth
Zero Current Output Slope
∆VOUT(Q)
Sensitivity Slope
Total Output Error2
∆Sens
ETOT
Min.
Typ.
Max.
0
–
30
Units
A
129
133
137
mV/A
–
15
–
mV
mV/°C
TA = –40°C to 25°C
–
0.06
–
TA = 25°C to 150°C
–
0.1
–
mV/°C
TA = –40°C to 25°C
–
0.007
–
mV/A/°C
TA = 25°C to 150°C
–
–0.025
–
mV/A/°C
IP = 30 A , IP applied for 5 ms; TA = 25°C
–
±1.5
–
%
1Device
may be operated at higher primary current levels, IP, and ambient temperatures, TA, provided that the Maximum Junction Temperature,
TJ(max), is not exceeded.
2Percentage of I , with I = 30 A. Output filtered.
P
P
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
5
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
Characteristic Performance
IP = 20 A, unless otherwise specified
Mean Supply Current versus Ambient Temperature
Supply Current versus Supply Voltage
10.5
11.2
10.4
11.0
10.3
10.8
VCC = 5 V
ICC (mA)
Mean ICC (mA)
10.2
10.1
10.0
10.6
10.4
9.9
10.2
9.8
10.0
9.7
9.8
9.6
-50
-25
0
25
50
75
100
125
9.6
4.5
150
4.6
4.7
4.8
4.9
TA (°C)
Magnetic Offset versus Ambient Temperature
ELIN (%)
–1.5
IOM (mA)
5.4
5.5
0.30
–1.0
–2.0
–2.5
VCC = 5 V; IP = 0 A,
After excursion to 20 A
–3.0
–3.5
0.25
0.20
0.15
0.10
–4.0
0.05
–4.5
–5.0
-50
-25
0
25
50
75
100
125
0
–50
150
–25
0
25
75
50
100
125
150
TA (°C)
TA (°C)
Mean Total Output Error versus Ambient Temperature
Sensitivity versus Ambient Temperature
10
188
8
187
Sens (mV/A)
6
ETOT (%)
5.3
Nonlinearity versus Ambient Temperature
–0.5
4
2
0
186
185
184
–2
–4
183
–6
–8
–50
182
–25
0
25
75
50
100
125
150
–50
–25
0
25
TA (°C)
Output Voltage versus Sensed Current
4.5
Sens (mV/A)
4.0
VCC = 5 V
3.5
3.0
TA (°C)
–40
–20
25
85
125
2.5
2.0
1.5
1.0
0.5
0
0
5
10
15
200.00
198.00
196.00
194.00
192.00
190.00
188.00
186.00
184.00
182.00
180.00
178.00
176.00
174.00
100
125
150
25
20
Sensitivity versus Sensed Current
TA (°C)
–40
25
85
150
0
5
10
IP (A)
0 A Output Voltage versus Ambient Temperature
15
Ip (A)
20
25
0 A Output Voltage Current versus Ambient Temperature
0.140
525
0.120
520
0.100
IP = 0 A
IP = 0 A
0.080
IOUT(Q) (A)
515
510
505
500
0.060
0.040
0.020
0
495
490
-50
75
50
TA (°C)
5.0
VIOUT (V)
5.2
0.35
0
VIOUT(Q) (mV)
5.0 5.1
VCC (V)
-0.020
-25
0
25
50
TA (°C)
75
100
125
150
-0.040
-50
-25
0
25
50
75
100
125
150
TA (°C)
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
6
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
Characteristic Performance
IP = 30 A, unless otherwise specified
Mean Supply Current versus Ambient Temperature
Supply Current versus Supply Voltage
10.1
10.8
10.0
10.6
ICC (mA)
Mean ICC (mA)
9.9
VCC = 5 V
90.8
9.7
10.4
10.2
10.0
9.6
9.8
9.5
9.6
9.4
-50
-25
0
25
50
75
100
125
9.4
4.5
150
4.6
4.7
4.8
4.9
TA (°C)
–0.5
ELIN (%)
–1.5
–2.0
–2.5
VCC = 5 V; IP = 0 A,
After excursion to 20 A
–3.0
–3.5
5.5
0.25
0.20
VCC = 5 V
0.15
0.10
–4.0
0.05
–4.5
–5.0
-50
-25
0
25
50
75
100
125
0
–50
150
–25
0
25
Mean Total Output Error versus Ambient Temperature
6
133.0
Sens (mV/A)
133.5
4
2
0
131.5
131.0
130.5
–6
130.0
25
75
50
100
125
129.5
–50
150
–25
0
25
Output Voltage versus Sensed Current
Sens (mV/A)
4.0
VCC = 5 V
3.0
TA (°C)
–40
–20
25
85
125
2.5
2.0
1.5
1.0
0.5
0
10
15
20
25
30
140
139
138
137
136
135
134
133
132
131
130
129
128
127
126
125
150
TA (°C)
–40
25
85
150
0
35
5
10
15
IP (A)
0 A Output Voltage versus Ambient Temperature
25
20
Ip (A)
30
35
0 A Output Voltage Current versus Ambient Temperature
514
0.080
512
0.060
510
IP = 0 A
508
IP = 0 A
0.040
IOUT(Q) (A)
506
504
502
0.020
0
500
498
-0.020
496
494
-50
125
Sensitivity versus Sensed Current
4.5
5
100
TA (°C)
5.0
0
75
50
TA (°C)
3.5
150
132.0
–4
0
125
132.5
–2
–25
100
Sensitivity versus Ambient Temperature
8
–8
–50
75
50
TA (°C)
TA (°C)
ETOT (%)
5.4
0.30
–1.0
VIOUT (V)
5.3
0.35
0
VIOUT(Q) (mV)
5.2
Nonlinearity versus Ambient Temperature
Magnetic Offset versus Ambient Temperature
IOM (mA)
5.0 5.1
VCC (V)
-25
0
25
50
TA (°C)
75
100
125
150
-0.040
-50
-25
0
25
50
75
100
125
150
TA (°C)
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
7
ACS713
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
Definitions of Accuracy Characteristics
Sensitivity (Sens). The change in device output in response to a
1 A change through the primary conductor. The sensitivity is the
product of the magnetic circuit sensitivity (G / A) and the linear
IC amplifier gain (mV/G). The linear IC amplifier gain is programmed at the factory to optimize the sensitivity (mV/A) for the
full-scale current of the device.
Noise (VNOISE). The product of the linear IC amplifier gain
(mV/G) and the noise floor for the Allegro Hall effect linear IC
(≈1 G). The noise floor is derived from the thermal and shot
noise observed in Hall elements. Dividing the noise (mV) by the
sensitivity (mV/A) provides the smallest current that the device is
able to resolve.
Linearity (ELIN). The degree to which the voltage output from
the IC varies in direct proportion to the primary current through
its full-scale amplitude. Nonlinearity in the output can be attributed to the saturation of the flux concentrator approaching the
full-scale current. The following equation is used to derive the
linearity:
{ [
100 1–
(VIOUT_full-scale amperes –VIOUT(Q) )
2 (VIOUT_half-scale amperes – VIOUT(Q))
[{
Accuracy is divided into four areas:
 0 A at 25°C. Accuracy at the zero current flow at 25°C, without the effects of temperature.
 0 A over Δ temperature. Accuracy at the zero current flow
including temperature effects.
 Full-scale current at 25°C. Accuracy at the the full-scale current
at 25°C, without the effects of temperature.
 Full-scale current over Δ temperature. Accuracy at the fullscale current flow including temperature effects.
Ratiometry. The ratiometric feature means that its 0 A output,
VIOUT(Q), (nominally equal to VCC × 0.1 ) and sensitivity, Sens, are
proportional to its supply voltage, VCC . The following formula is
used to derive the ratiometric change in 0 A output voltage,
VIOUT(Q)RAT (%).
100
100

VCC / 5 V
SensVCC / Sens5V

VCC / 5 V

Output Voltage versus Sampled Current
Accuracy at 0 A and at Full-Scale Current
Increasing VIOUT(V)
Accuracy
Over $Temp erature
Electrical offset voltage (VOE). The deviation of the device
output from its ideal quiescent value of VCC × 0.1 due to nonmagnetic causes. To convert this voltage to amperes, divide by the
device sensitivity, Sens.
Accuracy (ETOT). The accuracy represents the maximum deviation of the actual output from its ideal value. This is also known
as the total output error. The accuracy is illustrated graphically in
the output voltage versus current chart at right.

The ratiometric change in sensitivity, SensRAT (%), is defined as:
where VIOUT_full-scale amperes = the output voltage (V) when the
sampled current approximates full-scale ±IP .
Quiescent output voltage (VIOUT(Q)). The output of the device
when the primary current is zero. For a unipolar supply voltage,
it nominally remains at VCC × 0.1 . Thus, VCC = 5 V translates
into VIOUT(Q) = 0.5 V. Variation in VIOUT(Q) can be attributed to
the resolution of the Allegro linear IC quiescent voltage trim and
thermal drift.
VIOUT(Q)VCC / VIOUT(Q)5V
Accuracy
25°C Only
Average
VIOUT
Accuracy
Over $Temp erature
Accuracy
25°C Only
30 A
–IP (A)
+IP (A)
Full Scale
0A
Decreasing VIOUT(V)
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
8
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
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.
Primary Current
I (%)
Rise time (tr). The time interval between a) when the device
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 device, 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.
90
Transducer Output
10
0
t
Rise Time, tr
200
180
160
140
120
100
80
60
40
20
0
10000
IP = 5 A
0
1200
10
20
CF (nF)
30
40
Noise(p-p) (mA)
Rise Time versus External Filter Capacitance
CF (nF)
Expanded in chart at right
}
tr(μs)
Open
1
4.7
22
47
100
220
470
800
400
200
0
0.1
1
10
CF (nF)
100
1000
100
10
1
0.01
50
1000
600
Noise versus External Filter Capacitance
1000
IP = 0 A
tr (μs)
3.5
5.8
17.5
73.5
88.2
291.3
623
1120
tr(μs)
tPO (μs)
Noise vs. Filter Cap
Power on Time versus External Filter Capacitance
180
160
140
120
100
80
60
40
20
0
0.1
0.1
1
CF (nF)
10
100
1000
Rise Time versus External Filter Capacitance
1
10
100
CF (nF)
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
9
ACS713
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
Chopper Stabilization Technique
Chopper Stabilization is an innovative circuit technique that is
used to minimize the offset voltage of a Hall element and an associated on-chip amplifier. Allegro patented a Chopper Stabilization technique that nearly eliminates Hall IC output drift induced
by temperature or package stress effects. This offset reduction
technique is based on a signal modulation-demodulation process.
Modulation is used to separate the undesired DC offset signal
from the magnetically induced signal in the frequency domain.
Then, using a low-pass filter, the modulated DC offset is suppressed while the magnetically induced signal passes through
the filter. As a result of this chopper stabilization approach, the
output voltage from the Hall IC is desensitized to the effects
of temperature and mechanical stress. This technique produces
devices that have an extremely stable Electrical Offset Voltage,
are immune to thermal stress, and have precise recoverability
after temperature cycling.
This technique is made possible through the use of a BiCMOS
process that allows the use of low-offset and low-noise amplifiers
in combination with high-density logic integration and sample
and hold circuits.
Regulator
Clock/Logic
Amp
Sample and
Hold
Hall Element
Low-Pass
Filter
Concept of Chopper Stabilization Technique
10
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
Typical Applications
+5 V
+5 V
CBYP
0.1 μF
1
2
IP
IP+
CBYP
0.1 μF
R1
33 kΩ
VCC
IP+ VIOUT
8
RPU
100 kΩ
R2
100 kΩ
1
7
VOUT
4
3
ACS713
3
4
IP– FILTER
IP–
GND
6
5
R1
100 kΩ
5
–
+
2
Fault
1
IP+ VIOUT
IP
2 U1
LMV7235
VCC
IP+
CF
4
1
2
IP–
VCC
GND
IP+ VIOUT
1
+
7 VOUT
VREF
ACS713
IP1
3
4
IP– FILTER
IP–
GND
U1
LMC6772
–
2
4
VOUT
2
R3
3.3 kΩ
C1
1000 pF
+5 V
3
CF
IP+
VCC
IP+ VIOUT
CBYP
0.1 μF
8
+
7 VOUT
VREF
4
IP– FILTER
IP–
GND
U2
LMC6772
–
6
5
CF
Q4
2N7002
Q3
2N7002
Q1
FDS6675a
–
CF
0.01 μF
5
ACS713
IP2
6
5
3
LM321
5
6
VS2
CBYP
0.1 μF
8
+
Application 3. This configuration increases gain to 610 mV/A
(tested using the ACS712ELC-05A).
+5 V
IP+
7
1
RF
1 kΩ
IP– FILTER
D1
1N914
VS1
R2
100 kΩ
ACS713
3
Application 2. 10 A Overcurrent Fault Latch. Fault threshold
set by R1 and R2. This circuit latches an overcurrent fault
and holds it until the 5 V rail is powered down.
8
Q2
FDS6675a
R3
10 kΩ
R4
10 kΩ
R2
100 kΩ
R1
100 kΩ
LOAD
Application 4. Control circuit for MOSFET ORing.
11
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
Improving Sensing System Accuracy Using the FILTER Pin
In low-frequency sensing applications, it is often advantageous
to add a simple RC filter to the output of the device. Such a lowpass filter improves the signal-to-noise ratio, and therefore the
resolution, of the device output signal. However, the addition of
an RC filter to the output of a sensor IC can result in undesirable
device output attenuation — even for DC signals.
Signal attenuation, ∆VATT , is a result of the resistive divider
effect between the resistance of the external filter, RF (see Application 5), and the input impedance and resistance of the customer
interface circuit, RINTFC. The transfer function of this resistive
divider is given by:
⎛
⎞
⎟
⎝ RF + RINTFC ⎠
∆VATT = VIOUT ⎜
⎜
RINTFC
.
Even if RF and RINTFC are designed to match, the two individual
resistance values will most likely drift by different amounts over
temperature. Therefore, signal attenuation will vary as a function
of temperature. Note that, in many cases, the input impedance,
RINTFC , of a typical analog-to-digital converter (ADC) can be as
low as 10 kΩ.
The ACS713 contains an internal resistor, a FILTER pin connection to the printed circuit board, and an internal buffer amplifier. With this circuit architecture, users can implement a simple
RC filter via the addition of a capacitor, CF (see Application 6)
from the FILTER pin to ground. The buffer amplifier inside of
the ACS713 (located after the internal resistor and FILTER pin
connection) eliminates the attenuation caused by the resistive
divider effect described in the equation for ∆VATT. Therefore, the
ACS713 device is ideal for use in high-accuracy applications that
cannot afford the signal attenuation associated with the use of an
external RC low-pass filter.
+5 V
Pin 3 Pin 4
IP–
IP–
VCC
Pin 8
Allegro ACS706
Application 5. When a low pass filter is constructed externally to a standard Hall effect device,
a resistive divider may exist between the filter
resistor, RF, and the resistance of the customer interface circuit, RINTFC. This resistive divider
will cause excessive attenuation, as given by the
transfer function for ∆VATT.
Voltage
Regulator
To all subcircuits
0.1 MF
Filter
Dynamic Offset
Cancellation
VIOUT
Pin 7
Amp
Out
N.C.
Pin 6
Resistive Divider
Input
RF
Application
Interface
Circuit
Low Pass Filter
Temperature
Coefficient
Gain
Offset
CF
RINTFC
Trim Control
GND
Pin 5
IP+
IP+
Pin 1 Pin 2
+5 V
VCC
Pin 8
Allegro ACS713
Hall Current
Drive
IP+
Pin 1
IP+
Pin 2
IP–
Pin 3
Sense Temperature
Coefficient Trim
Buffer Amplifier
and Resistor
Dynamic Offset
Cancellation
Application 6. Using the FILTER pin
provided on the ACS713 eliminates
the attenuation effects of the resistor divider between RF and RINTFC,
shown in Application 5.
Signal
Recovery
VIOUT
Pin 7
Input
Application
Interface
Circuit
Sense
Trim
IP–
Pin 4
0 Ampere
Offset Adjust
RINTFC
GND
Pin 5
FILTER
Pin 6
CF
12
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
Package LC, 8-pin SOIC
4.90 ±0.10
8°
0°
8
0.65
6.00 ±0.20
2
Branded Face
8X
SEATING
PLANE
0.10 C
1.27 BSC
1
1.27
0.40
0.25 BSC
0.51
0.31
5.60
1.04 REF
A
1
C
1.27
1.75
0.25
0.17
3.90 ±0.10
8
C
2
PCB Layout Reference View
SEATING PLANE
GAUGE PLANE
NNNNNNN
TPP-AAA
LLLLL
1.75 MAX
0.25
0.10
1
B Standard Branding Reference View
For Reference Only; not for tooling use (reference MS-012AA)
Dimensions in millimeters
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
A Terminal #1 mark area
N = Device part number
T = Device temperature range
P = Package Designator
A = Amperage
L = Lot number
Belly Brand = Country of Origin
B Branding scale and appearance at supplier discretion
C
D
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
13
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 2.1 kVRMS Isolation and a Low-Resistance Current Conductor
ACS713
Revision History
Revision
Revision Date
Description of Revision
Rev. 12
November 16, 2012
Update rise time and isolation, IOUT reference data,
patents
Copyright ©2006-2013, Allegro MicroSystems, LLC
The products described herein are protected by U.S. patents: 5,621,319; 7,598,601; and 7,709,754.
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 life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the
failure of that life support device or system, or to affect the safety or effectiveness of that device or system.
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.
For the latest version of this document, visit our website:
www.allegromicro.com
14
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
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