ACS712 Allegro MicroSystems, Inc., ACS712 Datasheet - Page 12

• Manufacturer Part Number: ACS712
• Description: Fully Integrated, Hall Effect-based Linear Current Sensor With 2.1 Kvrms Voltage Isolation And A Low-resistance Current Conductor
• Manufacturer: Allegro MicroSystems, Inc.

ACS712
Application 2. Peak Detecting Circuit
Application 4. Rectified Output. 3.3 V scaling and rectification application
for A-to-D converters. Replaces current transformer solutions with simpler
ACS circuit. C1 is a function of the load resistance and filtering desired.
R1 can be omitted if the full range is desired.
I
P
C
0.1 μF
1
2
3
4
BYP
IP+
IP+
IP–
IP–
ACS712
I
P
+5 V
FILTER
VIOUT
C
0.1 μF
1
2
3
4
GND
VCC
BYP
IP+
IP+
IP–
IP–
ACS712
8
7
6
5
+5 V
FILTER
VIOUT
10 kΩ
R
GND
VCC
F
8
7
6
5
C
1 nF
1 MΩ
C
0.1 μF
R1
F
OUT
R
2 kΩ
33 kΩ
R2
F
V
V
OUT
C
1 nF
OUT
F
10 kΩ
R1
2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor
+
–
330 kΩ
R3
1N4448W
D1
U1
LT1178
C2
0.1 μF
10 kΩ
R4
C1
Fully Integrated, Hall Effect-Based Linear Current Sensor with
C1
0.1 μF
D1
1N914
A-to-D
Converter
Typical Applications
Q1
2N7002
V
V
PEAK
RESET
Application 5. 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.
Application 3. This configuration increases gain to 610 mV/A
(tested using the ACS712ELC-05A).
I
P
C
0.1 μF
1
2
3
4
BYP
IP+
IP+
IP–
IP–
I
ACS712
P
+5 V
FILTER
C
0.1 μF
VIOUT
1
2
3
4
BYP
VCC
GND
IP+
IP+
IP–
IP–
ACS712
+5 V
FILTER
8
7
6
5
VIOUT
VCC
GND
100 kΩ
R1
100 kΩ
R2
C
0.01 μF
8
7
6
5
F
R
1 kΩ
F
100 kΩ
R1
33 kΩ
R2
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
V
C
1 nF
OUT
F
1
3
+
–
5
4
2
3
3.3 kΩ
LM321
R3
+
–
4
5
2
D1
1N914
U1
LMV7235
1
V
C1
1000 pF
OUT
100 kΩ
R
PU
Fault
12