ACS709LLFTR-35BB-T Allegro Microsystems Inc, ACS709LLFTR-35BB-T Datasheet - Page 14

• Manufacturer Part Number: ACS709LLFTR-35BB-T
• Description: IC, CURRENT SENSOR, 11mA, QSOP-24
• Manufacturer: Allegro Microsystems Inc
• Series: -r

Specifications of ACS709LLFTR-35BB-T

• Quiescent Current: 11mA
• Bandwidth: 120kHz
• Sensor Case Style: QSOP
• No. Of Pins: 24
• Supply Voltage Range: 3V To 5.5V
• Operating Temperature Range: -40°C To +150°C
• Polarization: Unipolar
• Current - Sensing: ±75A
• Accuracy: ±3%
• Sensitivity: 28mV/A
• Current - Supply: 11mA
• Sensor Type: Hall Effect
• Voltage - Supply: 3 V ~ 5.5 V
• Output: 2.5V
• Frequency: 120kHz
• Response Time: 4µs
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 24-SSOP (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ACS709
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 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 device 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 V
sensed current approximates full-scale ±I
Symmetry (E
output from the device varies in proportion to either a positive
or negative full-scale primary current. The following formula is
used to derive symmetry:
Quiescent output voltage (V
when the primary current is zero. For a unipolar supply voltage,
it nominally remains at 0.5×V
bidirectional output device, V
2.5 V. Variation in V
the Allegro linear IC quiescent voltage trim and thermal drift.
Electrical offset voltage (V
put from its ideal quiescent voltage due to nonmagnetic causes. To
convert this voltage to amperes, divide by the device sensitivity,
Sens.
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 at right. Note that error is
directly measured during final test at Allegro.
100 1–
[ {
IOUT_full-scale amperes
NOISE
100
2 (V
LIN
TOT
SYM

). The product of the linear IC amplifier gain
V
V
V
IOUT
). The degree to which the voltage output from
IOUT
). The accuracy represents the maximum devia-
IOUT(Q)
IOUT
). The degree to which the absolute voltage
IOUT(Q)
_1/2 full-scale amperes – V
_+ full-scale amperes – V
_full-scale amperes – V
– V
IOUT
= the output voltage (V) when the
can be attributed to the resolution of
OE
IOUT(Q)
CC
CC
). The deviation of the device out-
_–full-scale amperes
. For example, in the case of a
= 5 V translates into V
). The output of the device
P
High Bandwidth, Fast Fault Response Current Sensor IC
.
IOUT(Q)
IOUT(Q)
IOUT(Q)

)
[ {
IOUT(Q)
=
–I
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-
Ratiometry. The ratiometric feature means that its 0 A output,
V
proportional to its supply voltage, V
used to derive the ratiometric change in 0 A output voltage,
V
The ratiometric change in sensitivity, Sens
P
(A)
IOUT(Q)
without the effects of temperature.
flow including temperature effects.
current at 25°C, without the effects of temperature.
scale current flow including temperature effects.
IOUT(Q)RAT
I
P
(min)
, (nominally equal to V
Output Voltage versus Sensed Current
In Thermally Enhanced Package
Accuracy at 0 A and at Full-Scale Current
O e
Accuracy
O e
v r
(%).
v r
Temp erature
Accuracy
25°C Only
Temp erature
100
25°C Only
Accuracy
Accuracy
100

V
IOUT(Q)VCC

Sens
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
V
VCC
V
0 A
CC
Increasing V
CC
Decreasing V
CC
/2) and sensitivity, Sens, are
/ 5 V
Average
/ Sens
/ 5 V
/ V
V
CC
IOUT
IOUT(Q)5V
IOUT
Accuracy
25°C Only
. The following formula is
IOUT
(V)
5V
Full Scale
(V)

RAT

(%), is defined as:
I
P
(max)
O e
Accuracy
v r
+I
Temp erature
P
(A)
14