ACS755 Allegro Micro Systems, Inc., ACS755 Datasheet - Page 4

• Manufacturer Part Number: ACS755
• Manufacturer: Allegro Micro Systems, Inc.

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 amplifi er gain (mV/G). The linear IC amplifi er gain is trimmed at the
factory to optimize the sensitivity (mV/A) for the full-scale current of the device.
Noise (V
The noise fl oor 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
full-scale amplitude. Nonlinearity in the output can be attributed to the saturation of the fl ux concentrator approaching the full-scale
current. The following equation is used to derive the linearity
where
Quiescent output voltage (V
nominally remains at 0.6 V. Variation in V
magnetic hysteresis, and thermal drift.
Electrical offset voltage (V
Magnetic offset error (I
netic 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 fl ux concentrator. The larger mag-
netic offsets are observed at the lower operating temperatures.
Accuracy (E
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 fl ow at 25°C, without the effects of temperature.
• 0 A over temperature: Accuracy of sensing zero current fl ow 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 fl ow including temperature effects.
ACS755050-DS, Rev. 2
Vout_¼ full-scale I
Vout_¾ full-scale I
NOISE
LIN
TOT
): The product of the linear IC amplifi er gain (mV/G) and the noise fl oor for the Allegro Hall effect linear IC (≈1 G).
): The degree to which the voltage output from the sensor varies in direct proportion to the primary current through its
): The accuracy represents the maximum deviation of the actual output from its ideal value. This is also known as the
P
P
(V) is the output voltage when the sensed current approximates 0.25 × I
(V) is the output voltage when the sensed current approximates 0.75 × I
ERROM
Nonlinearity (%) = 100
Current Sensor: ACS755xCB-050
OE
OUT(Q)
): The deviation of the device output from its ideal quiescent value due to nonmagnetic causes.
): The magnetic offset is due to the residual magnetism (remnant fi eld) of the core material. The mag-
): The output of the sensor when the primary current is zero. For a unipolar supply voltage, it
Defi nitions of Accuracy Characteristics
OUT(Q)
can be attributed to the resolution of the Allegro linear IC quiescent voltage trim,
1 –
3
V out _
V out _
1
3
/
/
4
4
full-scale I
full-scale I
P
P
–V
–V
OUT(Q)
OUT(Q)
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
P(max)
P(max)
, and
.
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