ACS755-050 Allegro MicroSystems, Inc., ACS755-050 Datasheet - Page 5

• Manufacturer Part Number: ACS755-050
• Description: Acs755 Current Sensors
• Manufacturer: Allegro MicroSystems, Inc.

ACS755xCB-050
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 pro-
grammed at the factory to optimize the sensitivity (mV/A) for the
full-scale current of the device.
Noise (V
(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
the sensor 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:
where
Quiescent output voltage (V
when the primary current is zero. For a unipolar supply voltage,
V
current approximates 0.25 × I
V
current approximates 0.75 × I
IOUT_¼ full-scale IP
IOUT_¾ full-scale IP
NOISE
100 1 –
LIN
). The product of the linear IC amplifier gain
). The degree to which the voltage output from
3
(V) is the output voltage when the sensed
(V) is the output voltage when the sensed

V
V
IOUT _
IOUT _
3
1
IOUT(Q)
/
/
4
4
full-scale IP
full-scale IP
P
P
(max), and
(max).
with High Voltage Isolation and a Low-Resistance Current Conductor
). The output of the sensor
– V
– V
IOUT(Q)
IOUT(Q)

Fully Integrated, Hall Effect-Based Linear Current Sensor
it nominally remains at 0.6. Variation in V
to the resolution of the Allegro linear IC quiescent voltage trim
and thermal drift.
Electrical offset voltage (V
put from its ideal quiescent value due to nonmagnetic causes.
Magnetic offset error (I
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
tion 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,
• 0 A over Δ temperature. Accuracy of sensing zero current
• Full-scale current at 25°C. Accuracy of sensing the full-scale
• Full-scale current over Δ temperature. Accuracy of sensing full-
without the effects of temperature.
flow including temperature effects.
current at 25°C, without the effects of temperature.
scale current flow including temperature effects.
TOT
). The accuracy represents the maximum devia-
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Worcester, Massachusetts 01615-0036 U.S.A.
OE
). The deviation of the device out-
). The magnetic offset is due to
IOUT(Q)
can be attributed
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