Current Sensor: ACS754SCB-200
The Allegro ACS754 family of current sensors provides economical and precise
solutions for current sensing in industrial, commercial, and communications
systems. The device package allows easy implementation by the customer. Typical
applications include: motor control, load detection and management, power distri-
bution, and overcurrent fault protection.
The sensor consists of a precision linear Hall IC, which is optimized to an internal
magnetic circuit to increase device sensitivity. The combination of a precisely
controlled self-aligning assembly process (patents pending), and the factory-pro-
grammed precision of the linear Hall sensor, result in high-level performance and
product uniformity.
The primary conductor used for current sensing (terminals 4 and 5) is designed
for extremely low power loss. These power terminals also are electrically isolated
from the sensor leads (pins 1, 2, and 3). This allows the ACS754 family of sensors
to be used in applications requiring electrical isolation, without using optoisolators
or other costly isolation techniques.
The output of this device has a positive slope (>V
CC
⁄
2) when an increasing cur-
rent
fl
ows from terminal 4 to terminal 5.
1
2
3
5
4
1
2
3
Package CB-PSF
5
4
The ACS754 family is provided in
lead-free packages (leadframe coating 100%
matte tin).
Package CB-PSS
Pin 1: VCC
Pin 2: GND
Pin 3: VOUT
Terminal 4: IP+
Terminal 5: IP–
Features and Benefits
•
•
•
•
•
•
•
•
•
Monolithic Hall IC for high reliability
Single +5 V supply
High isolation voltage
End-of-line factory-trimmed for gain and offset
Ultra-low power loss: low resistance of primary conductor
Ratiometric output from supply voltage
Low thermal drift of offset voltage
On-chip transient protection
Small package size, with easy mounting capability
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
..........................................
16 V
Output Voltage, V
OUT
........................................
16 V
Output Current Source, I
OUT(Source)
.................
3 mA
Output Current Sink, I
OUT(Sink)
.......................10
mA
Operating Temperature,
Ambient, T
A
, S range .......................
–20 to 85ºC
Maximum Junction, T
J(max)
.......................
165°C
Maximum Storage Temperature, T
S
...............
170°C
Applications
•
•
•
•
•
Industrial systems
Motor control
Servo systems
Power conversion
Battery monitors
TÜV America
Certificate Number:
U8V 04 11 54214 001
Use the following complete part numbers when ordering:
Part Number
ACS754SCB-200-PSF
ACS754SCB-200-PSS
Package
Formed signal pins
Straight signal pins
ACS754200-DS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 2003, Allegro MicroSystems, Inc.
Current Sensor: ACS754SCB-200
Functional Block Diagram
IP–
Terminal 5
+5V
VCC
Pin 1
Dynamic Offset
Cancellation
Amp
Out
VOUT
Pin 3
Filter
0.1
µF
GND
Pin 2
IP+
Terminal 4
2
ACS754200-DS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 2003, Allegro MicroSystems, Inc.
Current Sensor: ACS754SCB-200
ELECTRICAL CHARACTERISTICS,
over operating ambient temperature range unless otherwise stated
Characteristic
Symbol
Test Conditions
Min.
Primary Sensed Current
I
P
–200
Supply Voltage
V
CC
4.5
Supply Current
I
CC
V
cc
= 5.0 V, output open
6.5
Output Resistance
R
OUT
I
OUT
= 1.2 mA
–
Primary Conductor Resistance
R
PRIMARY
I
P
= ±50A; T
A
= 25°C
–
Isolation Voltage
V
ISO
Pins 1-3 and 4-5; 60 Hz, 1 minute
3.0
PERFORMANCE CHARACTERISTICS, -20°C to +85°C,
V
CC
= 5 V unless otherwise specified
Propagation time
t
PROP
I
P
= ±100 A, T = 25°C
–
Response time
t
RESPONSE
I
P
= ±100 A, T = 25°C
–
Rise time
Frequency Bandwidth
Sensitivity
Noise
Nonlinearity
Symmetry
Zero Current Output Voltage
Electrical Offset Voltage
(Magnetic error not included)
Magnetic Offset Error
Total Output Error
(Including all offsets)
t
r
f
Sens
V
NOISE
E
LIN
E
SYM
V
OUT(Q)
V
OE
V
OM
E
TOT
I
P
= ±100 A, T = 25°C
–3 dB, T = 25°C
±I
P
, T = 25°C
±I
P
Peak-to-peak, T = 25°C,
no external filter
±I
P
±I
P
I = 0 A, T = 25°C
I = 0 A, T = 25°C
I=0A
I = 0 A, after excursion of 200 A
±I
P
, T = 25°C
±I
P
–
–
–
9.5
–
–
98
–
–10
–20
–
–
–
Typ.
–
5.0
8
1
100
–
4
11
10
35
10.0
–
35
–
100
2.5
–
–
±0.15
±1.0
–
Max.
200
5.5
10
2
–
–
–
–
–
–
–
10.5
–
Units
A
V
mA
Ω
μΩ
kV
μs
μs
μs
kHz
mV/A
mV/A
mV
%
%
V
mV
mV
A
%
%
±0.8
102
–
10
20
±0.50
–
±5.0
3
ACS754200-DS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 2003, Allegro MicroSystems, Inc.
Current Sensor: ACS754SCB-200
Definitions of Accuracy Characteristics
Sensitivity (Sens):
The change in sensor 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 trimmed at the
factory to optimize the sensitivity (mV/A) for the full-scale current of the device.
Noise (V
NOISE
):
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 (E
LIN
):
The degree to which the voltage output from the sensor varies in direct proportion to the primary current through
its full-scale amplitude. Linearity reveals the maximum deviation from the ideal transfer curve for this transducer. Nonlinearity in the
output can be attributed to the gain variation across temperature and saturation of the flux concentrator approaching the full-scale cur-
rent. The following equation is used to derive the linearity:
100 1–
{ [
½½gain ½½%
sat (
V
out_full-scale amperes –
V
OUT(Q)
)
2 (Vout_half-scale amperes –
V
OUT(Q)
)
[{
where
∆ gain = the gain variation as a function of temperature changes from 25ºC,
% sat = the percentage of saturation of the flux concentrator, which becomes significant as the current
being sensed approaches full-scale ±I
P
, and
V
out_full-scale amperes
= the output voltage (V) when the sensed current approximates full-scale ±I
P
.
Symmetry (E
SYM
):
The degree to which the absolute voltage output from the sensor varies in proportion to either a positive or nega-
tive full-scale primary current. The following equation is used to derive symmetry:
100
[
V
out_+full-scale amperes –
V
OUT(Q)
V
OUT(Q)
–Vout_–full-scale amperes
[
Quiescent output voltage (V
OUT(Q)
):
The output of the sensor when the primary current is zero. For a unipolar supply voltage, it
nominally remains at V
CC
⁄ 2. Thus, V
CC
= 5 V translates into V
OUT(Q)
= 2.5 V. Variation in V
OUT(Q)
can be attributed to the resolution
of the Allegro linear IC quiescent voltage trim, magnetic hysteresis, and thermal drift.
Electrical offset voltage (V
OE
):
The deviation of the device output from its ideal quiescent value of V
CC
⁄ 2 due to nonmagnetic causes.
Magnetic offset error (V
OM
):
The magnetic offset is due to the residual magnetism (remnant field) of the core material. The magnetic
offset error is highest when the magnetic circuit has been saturated, usually when the device has been subjected to a full-scale or high-
current overload condition. The magnetic offset is largely dependent on the material used as a flux concentrator. The larger magnetic
offsets are observed at the lower operating temperatures.
Accuracy (E
TOT
):
The accuracy represents the maximum deviation of the actual output from its ideal value. This is also known as the
total ouput error. The accuracy is illustrated graphically in the Output Voltage versus Current chart on the following page.
Accuracy is divided into four areas:
•
0 A at 25°C:
Accuracy of sensing zero current flow at 25°C, without the effects of temperature.
•
0 A over temperature:
Accuracy of sensing zero current flow including temperature effects.
•
Full-scale current at 25°C:
Accuracy of sensing the full-scale current at 25°C, without the effects of temperature.
•
Full-scale current over Δ temperature:
Accuracy of sensing full-scale current flow including temperature effects.
4
ACS754200-DS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 2003, Allegro MicroSystems, Inc.
Current Sensor: ACS754SCB-200
Output voltage vs. current, illustrating sensor accuracy at 0 A and at full-scale current
Increasing V
OUT
(V)
Accuracy
Over
½Temperature
Accuracy
25°C Only
Average
V
OUT
Accuracy
Over
½Temperature
Accuracy
25°C Only
200 A
–I
P
(A)
–200 A
+I
P
(A)
Full Scale
0A
Accuracy
25°C Only
Accuracy
Over
½Temperature
Decreasing V
OUT
(V)
5
ACS754200-DS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 2003, Allegro MicroSystems, Inc.
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