Fully Integrated, Hall Effect-Based Linear Current Sensor IC
with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor
ACS756
Definitions of Dynamic Response Characteristics
Power-On Time (tPO). When the supply is ramped to its operat-
ing 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.
Rise time (tr). The time interval between a) when the device
reaches 10% of its full scale value, and b) when it reaches 90%
of its full scale value. The rise time to a step response is used to
derive the bandwidth of the device, in which ƒ(–3 dB) = 0.35/tr.
Both tr and tRESPONSE are detrimentally affected by eddy current
losses observed in the conductive IC ground plane.
Primary Current
I (%)
90
Output Voltage versus Sampled Current
Total Output Error at 0 A and at Half-Scale Current
Transducer Output
10
0
t
Rise Time, t
r
Increasing VIOUT(V)
Accuracy
Over $Temp erature
Accuracy
25°C Only
Average
V
IOUT
Propagation delay (tPROP). The time required for the device
output to reflect a change in the primary current signal. Propaga-
tion delay is attributed to inductive loading within the linear IC
package, as well as in the inductive loop formed by the primary
conductor geometry. Propagation delay can be considered as a
fixed time offset and may be compensated.
Accuracy
Over $Temp erature
Accuracy
25°C Only
IP(min)
–IP (A)
+IP (A)
Half Scale
IP(max)
Primary Current
I (%)
90
0 A
Transducer Output
Accuracy
25°C Only
0
t
Propagation Time, tPROP
Accuracy
Over $Temp erature
Decreasing VIOUT(V)
Allegro MicroSystems, Inc.
115 Northeast Cutoff
8
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
