ACS715LLCTR-20A-T Allegro Microsystems Inc, ACS715LLCTR-20A-T Datasheet - Page 11

• Manufacturer Part Number: ACS715LLCTR-20A-T
• Description: IC, LINEAR CURRENT SENSOR, 10mA, 8-SOIC
• Manufacturer: Allegro Microsystems Inc
• Series: -r

Specifications of ACS715LLCTR-20A-T

• Quiescent Current: 10mA
• Bandwidth: 80kHz
• Sensor Case Style: SOIC
• No. Of Pins: 8
• Supply Voltage Range: 4.5V To 5.5V
• Operating Temperature Range: -40°C To +150°C
• Polarization: Unipolar
• Current - Sensing: 20A
• Accuracy: ±1.5%
• Sensitivity: 185mV/A
• Current - Supply: 10mA
• Sensor Type: Hall Effect
• Voltage - Supply: 4.5 V ~ 5.5 V
• Output: 500mV
• Frequency: 80kHz
• Response Time: 5µs
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ACS715
Chopper Stabilization Technique
Chopper Stabilization Technique
Chopper Stabilization is an innovative circuit technique that is
used to minimize the offset voltage of a Hall element and an asso-
ciated on-chip amplifier. Allegro patented a Chopper Stabiliza-
tion technique that nearly eliminates Hall IC output drift induced
by temperature or package stress effects. This offset reduction
technique is based on a signal modulation-demodulation process.
Modulation is used to separate the undesired DC offset signal
from the magnetically induced signal in the frequency domain.
Then, using a low-pass filter, the modulated DC offset is sup-
pressed while the magnetically induced signal passes through
the filter. As a result of this chopper stabilization approach, the
output voltage from the Hall IC is desensitized to the effects
of temperature and mechanical stress. This technique produces
devices that have an extremely stable Electrical Offset Voltage,
are immune to thermal stress, and have precise recoverability
after temperature cycling.
Typical Applications
Application 2. 10 A Overcurrent Fault Latch. Fault threshold
set by R1 and R2. This circuit latches an overcurrent fault
and holds it until the 5 V rail is powered down.
I
P
Application 4. Control circuit for MOSFET ORing.
C
0.1 μF
1
2
3
4
BYP
IP+
IP+
IP–
IP–
ACS715
+5 V
FILTER
VIOUT
GND
VCC
8
7
6
5
100 kΩ
R1
33 kΩ
R2
C
V
F
OUT
4
3
+
–
5
Automotive Grade, Fully Integrated, Hall Effect-Based Linear Current Sensor IC
2
D1
1N914
U1
LMV7235
1
with 2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor
100 kΩ
R
PU
I
P1
Fault
V
Q1
FDS6675a
S1
1
2
3
4
IP+
IP+
IP–
IP–
ACS715
100 kΩ
R1
FILTER
VIOUT
GND
VCC
This technique is made possible through the use of a BiCMOS
process that allows the use of low-offset and low-noise amplifiers
in combination with high-density logic integration and sample
and hold circuits.
8
7
6
5
Application 3. This configuration increases gain to 610 mV/A
(tested using the ACS712ELC-05A).
Hall Element
V
OUT
I
P
C
10 kΩ
R3
C
0.1 μF
F
1
2
3
4
BYP
V
IP+
IP+
IP–
IP–
REF
ACS715
C
0.1 μF
BYP
+5 V
FILTER
VIOUT
+
–
GND
Regulator
VCC
Concept of Chopper Stabilization Technique
+5 V
Q3
2N7002
U1
LMC6772
8
7
6
5
100 kΩ
R1
100 kΩ
R2
LOAD
C
0.01 μF
F
R
1 kΩ
F
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
I
P2
V
Q2
FDS6675a
S2
1
2
3
4
1
3
IP+
IP+
IP–
IP–
ACS715
+
–
100 kΩ
R2
FILTER
VIOUT
VCC
GND
Clock/Logic
5
2
Amp
3.3 kΩ
LM321
R3
4
8
7
6
5
V
OUT
C
10 kΩ
R4
F
V
C1
1000 pF
OUT
V
REF
C
0.1 μF
BYP
+
–
+5 V
Low-Pass
Filter
Q4
2N7002
U2
LMC6772
11