ACS718 Datasheet

ACS718
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
FEATURES AND BENEFITS
• IEC/UL 60950-1 Ed. 2 certified to:
□□ Dielectric Strength = 4800 Vrms (tested for 60 seconds)
□□ Basic Isolation = 1550 Vpeak
□□ Reinforced Isolation = 800 Vpeak
• Small footprint, low-profile SOIC16 wide-body package
suitable for space constrained applications that require
high galvanic isolation
• 0.85mΩ primary conductor for low power loss and high
inrush current withstand capability
• Low, 350 μARMS/√Hz noise density results in typical
input referred noise of 70 mA(rms) at max bandwidth (40
kHz)
• 5.0 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
• Ratiometric output from supply voltage
pe d
Ty ste
te
TÜV America
Certificate Number:
U8V 14 11 54214 030
CB 14 11 54214 029
CB Certificate Number:
US-22339-A1-UL
Package: 16-Pin SOICW (suffix MA)
GND
NC
ACS718
NC
VIOUT
–IP
5
IP–
6
IP–
7
IP–
8
IP–
The device consists of a 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 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 through 4, to pins 5 through 8), which is the path used for
current sensing. The internal resistance of this conductive path
is 0.85 mΩ typical, providing low power loss.
The ACS718 is provided in a small, low profile surface mount
SOICW16 package (suffix MA). The device is lead (Pb) free
with 100% matte tin leadframe plating. The device is fully
calibrated prior to shipment from the factory.
NC
1
IP+
2
IP+
3
IP+
4
IP+
IP
The Allegro™ ACS718 current sensor IC is an economical, high
isolation solution for AC or DC current sensing in industrial,
commercial, and communications systems. The small package is
ideal for space constrained applications, though the wide-body
provides the creepage and clearance needed for high isolation.
Typical applications include motor control, load detection and
management, switched-mode power supplies, and overcurrent
fault protection.
The terminals of the conductive path are electrically isolated
from the sensor leads (pins 10 through 15 ). This allows the
ACS718 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.
Approximate Scale 1:1
+IP
DESCRIPTION
NC
VCC
NC
16
15
14
13
12
11
10
9
Typical Application
ACS718-DS, Rev. 1
CL
The ACS718 outputs an
analog signal, VIOUT , that
changes, proportionally,
with the bidirectional AC
or DC primary sensed
current, IP , within the
specified measurement
range.
CBYPASS
0.1 µF
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
SPECIFICATIONS
Selection Guide
Part Number
IP
(A)
Sens(Typ)
at VCC = 5.0 V
(mV/A)
ACS718KMATR-10B-T2
±10
200
ACS718KMATR-20B-T2
±20
100
TA
(°C)
Packing1
-40 to 125
Tape and reel, 1000 pieces per reel
1Contact Allegro
2Varient
for additional packing options.
not intended for automotive applications.
Absolute Maximum Ratings
Characteristic
Symbol
Notes
Rating
Units
Supply Voltage
VCC
7
V
Reverse Supply Voltage
VRCC
–0.1
V
Output Voltage
VIOUT
25
V
Reverse Output Voltage
VRIOUT
–0.1
V
Operating Ambient Temperature
TA
–40 to 125
°C
Junction Temperature
TJ(max)
Range K
165
°C
Storage Temperature
Tstg
–65 to 165
°C
Rating
Unit
4800
VRMS
1550
VPK
1097
VRMS or
VDC
Isolation Characteristics
Characteristic
Dielectric Strength Test Voltage
Symbol
VISO
Notes
Agency type tested for 60 seconds per IEC/UL 60950-1 (2nd
Edition). Production tested for 1 second at 3000 VRMS in
accordance with IEC/UL 60950-1 (2nd Edition).
Working Voltage for Basic Isolation
VWVBI
Maximum approved working voltage for basic (single) isolation
according IEC/UL 60950-1 (2nd Edition)
VWVRI
Maximum approved working voltage for reinforced isolation
according to IEC/UL 60950-1 (2nd Edition)
800
Working Voltage for Reinforced Isolation
VPK
565
VRMS or
VDC
Clearance
Dcl
Minimum distance through air from IP leads to signal leads.
7.5
mm
Creepage*
Dcr
Minimum distance along package body from IP leads to signal
leads.
8.2
mm
*In order to maintain this creepage in applications, the user should add a slit in the PCB under the package. Otherwise, the pads on the PCB will reduce the creepage.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
2
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
VCC
VCC
Master Current
Supply
To all subcircuits
CBYP
Hall Current
Drive
IP+
Tuned Filter
Dynamic Offset
Cancellation
IP+
Power-on
Reset
VIOUT
CLOAD
IP−
Sensitivity and
Sensitivity TC
IP−
Offset and
Offset TC
GND
Functional Block Diagram
Pin-out Diagram and Terminal List Table
IP+ 1
16 NC
IP+ 2
15 GND
IP+ 3
14 NC
IP+ 4
IP– 5
IP– 6
11 NC
IP– 7
10 VCC
IP– 8
9 NC
Terminal List
Number
Name
13 NC
1, 2, 3, 4
IP+
Terminals for current being sensed; fused internally
12 VIOUT
5, 6, 7, 8
IP–
Terminals for current being sensed; fused internally
9, 16
NC
No internal connection; recommended to be left unconnected in order to maintain
high creepage.
11, 13. 14
NC
No internal connection; recommended to connect to GND for the best ESD
performance
10
VCC
12
VIOUT
15
GND
Package MA, 16-Pin
SOICW
Description
Device power supply terminal
Analog output signal
Signal ground terminal
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
3
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
COMMON ELECTRICAL CHARACTERISTICS1: TA Range K, valid at TA = – 40°C to 125°C, VCC = 5 V, unless otherwise specified
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
4.5
5
5.5
V
7
9
mA
–
1
nF
Supply Voltage
VCC
Supply Current
ICC
VCC = 5 V, output open
–
Output Capacitance Load
CL
VIOUT to GND
–
Output Resistive Load
RL
VIOUT to GND
15
–
–
kΩ
Primary Conductor Resistance
RP
TA = 25°C
–
0.85
–
mΩ
IP = IP(max), TA = 25°C, CL = open
–
10
–
μs
–
4.5
–
G/A
IP = IP(max), TA = 25°C, CL = open
–
5
–
μs
Rise Time
tr
Magnetic Coupling Factor
CF
Propagation Delay
tpd
Response Time
tRESPONSE
IP = IP(max), TA = 25°C, CL = open
–
13
–
μs
Internal Bandwidth
BWi
Small signal –3 dB
–
40
–
kHz
Noise Density
IND
Input referenced noise density;
TA = 25°C, CL = 1 nF
–
350
–
µA(rms)/
√Hz
Noise
IN
Input referenced noise; BWi = 40 kHz,
TA = 25°C, CL = 1 nF
–
70
–
mA(rms)
ELIN
Across full range of IP
–
±1
–
%
VOH
RL = RL(min)
VCC – 0.3
–
–
V
VOL
RL = RL(min)
–
–
0.3
V
tPO
Output reaches 90% of steady-state
level, TA = 25°C, IP = IP(max)
–
35
–
μs
Nonlinearity
Saturation Voltage2
Power-On Time
1Device
may be operated at higher primary current levels, IP , ambient temperatures, TA , and internal leadframe temperatures, provided the Maximum Junction Temperature, TJ(max), is not exceeded.
2The sensor IC will continue to respond to current beyond the range of I until the high or low saturation voltage; however, the nonlinearity in this region will be worse than
P
through the rest of the measurement range.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
4
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
xKMATR-10B PERFORMANCE CHARACTERISTICS: valid at TA = – 40°C to 125°C, VCC = 5 V, unless otherwise speci-
fied
Characteristic
Symbol
Test Conditions
Min.
Typ.1
Max.
Units
Nominal Performance
Current Sensing Range
IPR
Sensitivity
Sens
Zero Current Output Voltage
VIOUT(Q)
-10
-
10
A
IPR (min) < IP < IPR (max)
-
200
-
mV/A
Bidirectional; IP = 0 A
-
Vcc x
0.5
-
V
Accuracy Performance
Total Output Error2
Total Output Error
ETOT
Components3
Sensitivity Error
IP = IPR(max); TA = 25°C
-5
±2
5
IP = IPR(max); TA = 85°C
-
±2
-
IP =IPR(max); TA = 125°C
-
±4
-
IP = IPR(max); TA = -40°C
-
±4
-
TA = 25°C; measured at IP = IPR(max)
-4
±2
4
TA = 85°C; measured at IP = IPR(max)
-
±2
-
TA = 125°C; measured at IP = IPR(max)
-
±3
-
ETOT = ESENS + 100 × VOE/(Sens x IP)
ESENS
TA = -40°C; measured at IP = IPR(max)
Offset Voltage4
%
VOE
%
-
±4
-
TA = 25°C; IP = 0 A;
-40
±10
40
TA = 85°C; IP = 0 A;
-
±15
-
TA = 125°C; IP = 0 A;
-
10 ±20
-
TA = -40°C; IP = 0 A
-
±25
-
–
±2
–
%
–
±2
–
%
mV
Lifetime Drift Characteristics
Sensitivity Error Lifetime Drift
Total Output Error Lifetime Drift
ESENS_
DRIFT
ETOT_DRIFT
1 Typical
values with ± are 3 sigma values.
2 Percentage of I , with I = I
P P
PR (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.
4 Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
5
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
xKMATR-20B PERFORMANCE CHARACTERISTICS: valid at TA = – 40°C to 125°C, VCC = 5 V, unless otherwise speci-
fied
Characteristic
Symbol
Test Conditions
Min.
Typ.1
Max.
Units
Nominal Performance
Current Sensing Range
IPR
Sensitivity
Sens
Zero Current Output Voltage
VIOUT(Q)
-20
-
20
A
IPR (min) < IP < IPR (max)
-
100
-
mV/A
Bidirectional; IP = 0 A
-
Vcc x
0.5
-
V
Accuracy Performance
Total Output Error2
Total Output Error
ETOT
Components3
Sensitivity Error
IP = IPR(max); TA = 25°C
-5
±2
5
IP = IPR(max); TA = 85°C
-
1 ±2
-
IP =IPR(max); TA = 125°C
-
2 ±3
-
IP = IPR(max); TA = -40°C
-
±3
-
TA = 25°C; measured at IP = IPR(max)
-4
±2
4
TA = 85°C; measured at IP = IPR(max)
-
1 ±2
-
TA = 125°C; measured at IP = IPR(max)
-
2 ±3
-
ETOT = ESENS + 100 × VOE/(Sens x IP)
ESENS
TA = -40°C; measured at IP = IPR(max)
Offset Voltage4
%
VOE
%
-
±3
-
TA = 25°C; IP = 0 A;
-40
±8
40
TA = 85°C; IP = 0 A;
-
±10
-
TA = 125°C; IP = 0 A;
-
±15
-
TA = -40°C; IP = 0 A
-
±15
-
–
±2
–
%
–
±2
–
%
mV
Lifetime Drift Characteristics
Sensitivity Error Lifetime Drift
Total Output Error Lifetime Drift
ESENS_
DRIFT
ETOT_DRIFT
1 Typical
values with ± are 3 sigma values.
2 Percentage of I , with I = I
P P
PR (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.
4 Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
6
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
CHARACTERISTIC PERFORMANCE
xKMATR-10B Key Parameters
Zero Current Output Voltage vs. Temperature
Offset Voltage vs. Temperature
2540
40
2530
30
Offset Voltage (mV)
VIOUT(Q) (mV)
2520
2510
2500
2490
10
0
-10
-20
2480
2470
-50
20
-30
-25
0
25
50
75
100
125
-50
-25
0
Temperature (ºC)
4.00
206
3.00
204
2.00
Sensitivity Error (%)
Sensitivity (mV/A)
208
202
200
198
196
194
192
100
125
100
125
100
125
1.00
0.00
-1.00
-2.00
-3.00
-5.00
-25
0
25
50
75
100
125
-50
-25
0
Temperature (ºC)
25
50
75
Temperature (ºC)
Total Error at IPR(max) vs. Temperature
Nonlinearity vs. Temperature
0.80
5.00
0.60
4.00
3.00
Total Error (%)
0.40
Nonlinearity (%)
75
-4.00
190
0.20
0.00
-0.20
-0.40
2.00
1.00
0.00
-1.00
-2.00
-3.00
-0.60
-4.00
-5.00
-0.80
-50
50
Sensitivity Error vs. Temperature
Sensitivity vs. Temperature
-50
25
Temperature (ºC)
-25
0
25
50
75
100
125
-50
Temperature (ºC)
-25
0
25
50
75
Temperature (ºC)
+3 Sigma
Average
-3 Sigma
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
7
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
xKMATR-20B Key Parameters
Offset Voltage vs. Temperature
2520
20
2515
15
2510
10
Offset Voltage (mV)
VIOUT(Q) (mV)
Zero Current Output Voltage vs. Temperature
2505
2500
2495
0
-5
-10
2490
-15
2485
-50
5
-25
0
25
50
75
100
125
-50
-25
0
Temperature (ºC)
5.00
104
4.00
103
3.00
Sensitivity Error (%)
Sensitivity (mV/A)
105
102
101
100
99
98
97
100
125
2.00
1.00
0.00
-1.00
-2.00
-25
0
25
50
75
100
-4.00
-50
125
-25
0
Temperature (ºC)
25
50
75
100
125
100
125
Temperature (ºC)
Total Error at IPR(max) vs. Temperature
Nonlinearity vs. Temperature
0.60
-5.00
0.50
4.00
0.40
3.00
0.30
0.20
Total Error (%)
Nonlinearity (%)
75
-3.00
96
0.00
0.00
-0.10
2.00
1.00
0.00
-1.00
-0.20
-0.30
-2.00
-0.40
-50
50
Sensitivity Error vs. Temperature
Sensitivity vs. Temperature
-50
25
Temperature (ºC)
-3.00
-25
0
25
50
75
100
125
-50
Temperature (ºC)
-25
0
25
50
75
Temperature (ºC)
+3 Sigma
Average
-3 Sigma
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
8
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
DEFINITIONS OF ACCURACY CHARACTERISTICS
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.
Increasing
VIOUT (V)
{ [
100 1–
∆ gain × % sat ( VIOUT_full-scale amperes – VIOUT(Q) )
2 (VIOUT_half-scale amperes – 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 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 = 5 V translates
into VIOUT(Q) = 2.5 V. Variation in VIOUT(Q) can be attributed to
the resolution of the Allegro linear IC quiescent voltage trim and
thermal drift.
Accuracy at
25°C Only
IPR(min)
ETOT(IP) =
VIOUT_ideal(IP) – VIOUT(IP)
Sensideal(IP) × IP
+IP (A)
VIOUT(Q)
–IP (A)
Full Scale IP
IPR(max)
0A
Accuracy at
25°C Only
Decreasing
VIOUT (V)
Accuracy Across
Temperature
Figure 1: Output Voltage versus Sensed Current
+ETOT
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 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:
Accuracy at
25°C Only
Ideal VIOUT
Accuracy Across
Temperature
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:
Accuracy Across
Temperature
Across Temperature
25°C Only
–IP
+IP
× 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 figures
1 and 2. Figure 1 shows a distribution of output voltages versus IP
at 25°C and across temperature. Figure 2 shows the corresponding ETOT versus IP .
–ETOT
Figure 2: Total Output Error versus Sensed Current
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
9
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
APPLICATION INFORMATION
The ACS718 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 external 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:
B
Error(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
0.22 A of error. If the ACS718KMATR-10B, which has a nominal
sensitivity of 200 mV/A, is being used, that equates to 44 mV of
error on the output of the sensor.
Table 1: External Magnetic Field (Gauss) Impact
External Field
(Gauss)
Error (A)
0.5
Error (mV)
10B
20B
0.11
22
11
1
0.22
44
22
2
0.44
88
44
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 components 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:
2
ETOT(IP) = ESENS +
(
2
)
100 × VOE
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:
ETOTAVG (IP) = ESENSAVG +
100 × VOEAVG
Sens × IP
The resulting total error will be a sum of ETOT and ETOT_AVG.
Using these equations and the 3 sigma distributions for Sensitivity Error and Offset Voltage, the Total Error vs. sensed current
(IP) is below for the ACS718KMATR-20B. As expected, as one
goes towards zero current, the error in percent goes towards infinity due to division by zero (refer to Figure 3).
8
Total Error (% of current measured)
Impact of External Magnetic Fields
6
4
2
-40C+3sig
-40C-3sig
0
25C+3sig
25C-3sig
-2
125C+3sig
-4
125C-3sig
-6
-8
0
2
4
6
8
10
12
14
16
18
20
Current (A)
Figure 3: Predicted Total Error as a Function of Sensed
Current for the ACS718KMATR-20B
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
10
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
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.
V
VCC(min.)
t1
tPO
t2= time at which output voltage settles
within ±10% of its steady state value
under an applied magnetic field
Propagation Delay (tpd )
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.
t2
t1= time at which power supply reaches
minimum specified operating voltage
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.
Response Time (tRESPONSE)
VIOUT
90% VIOUT
Rise Time (tr)
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.
VCC
VCC(typ.)
0
t
Figure 4: Power-On Time (tPO)
(%)
90
Primary Current
VIOUT
Rise Time, tr
20
10
0
Propagation Delay, tpd
t
Figure 5: Rise Time (tr) and Propagation Delay (tpd)
(%)
90
Primary Current
VIOUT
Response Time, tRESPONSE
0
Figure 6: Response Time (tRESPONSE)
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
t
11
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
HIGH ISOLATION PCB LAYOUT
NOT TO SCALE
All dimensions in millimeters.
15.75
9.54
0.65
1.27
Package Outline
Slot in PCB to maintain >8 mm creepage
once part is on PCB
2.25
7.25
1.27
3.56
17.27
Current
Out
Current
In
21.51
Perimeter holes for stitching to the other,
matching current trace design, layers of
the PCB for enhanced thermal capability.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
12
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
PACKAGE OUTLINE DRAWING
For Reference Only – Not for Tooling Use
(Reference MS-013AA)
NOT TO SCALE
Dimensions in millimeters
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
8°
0°
10.30 ±0.20
16
0.33
0.20
7.50 ±0.10
10.30 ±0.33
A
1
1.27 1.40 REF
0.40
2
Branded Face
0.25 BSC
SEATING PLANE
16X
C
2.65 MAX
0.10
C
GAUGE PLANE
SEATING
PLANE
0.30
0.10
1.27 BSC
0.51
0.31
0.65
1.27
16
NNNNNNNNNNNN
YYWW
LLLLLLLLLLLL
2.25
1
9.50
1
C
2
PCB Layout Reference View
B
Standard Branding Reference View
N = Device part number
= Supplier emblem
Y = Last two digits of year of manufacture
W = Week of manufacture
L = Lot number
A
Terminal #1 mark area
B
Branding scale and appearance at supplier discretion
C Reference land pattern layout (reference IPC7351 SOIC127P600X175-8M);
all pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances
Figure 7: Package MA, 16-pin SOICW
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
13
High Isolation Linear Current Sensor IC with
850 µΩ Current Conductor
ACS718
Revision History
Revision
Revision Date
–
December 15, 2014
1
June 15, 2015
Description of Revision
Initial Release
Corrected pinout diagram
Copyright ©2011-2015, 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 life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the
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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:
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Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
14
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