Data Sheet
ACHS-7121/7122/7123
Fully Integrated, Hall Effect-Based Linear
Current Sensor IC with 3 kV
RMS
Isolation and
Low-Resistance Current Conductor
Overview
The Broadcom
®
ACHS-7121/7122/7123 product series is a
fully integrated Hall Effect-based isolated linear current sensor
device family designed for AC or DC current sensing in
industrial, commercial, and communications systems. Each of
the ACHS-7121/7122/7123 consists of a precise, low-offset,
linear Hall circuit with a copper conduction path located near
the surface of the die. Applied current flowing through this
copper conduction path generates a magnetic field that the Hall
IC converts into a proportional voltage. Device accuracy is
optimized through the close proximity of the magnetic signal to
the Hall transducer.
A precise, proportional voltage is provided by the low-offset,
chopper-stabilized CMOS Hall IC, which is programmed for
accuracy after packaging. The output of the device has a
positive slope (>V
OUT(Q)
) when an increasing current flows
through the primary copper conduction path (from pins 1 and 2,
to pins 3 and 4), which is the path used for current sampling.
The internal resistance of this conductive path is 0.7 mΩ
typical, providing low-power loss. The terminals of the
conductive path are electrically isolated from the signal leads
(pins 5 through 8). This performance is delivered in a compact,
surface mountable, SO-8 package that meets worldwide
regulatory safety standards.
Part Number
ACHS-7121
ACHS-7122
ACHS-7123
Current Range
±10A
±20A
±30A
Sensitivity
185 mV/A
100 mV/A
66 mV/A
Features
Wide Operating Temperature: –40ºC to 110ºC
Primary conductor resistance: 0.7 mΩ typ.
Sensing current range: ±10A, ±20A, and ±30A
Output sensitivity: 66 to 185 mV/A
Output voltage proportional to AC or DC currents
Ratiometric output from supply voltage
Single supply operation: 5.0V
Low-noise analog signal path
Device bandwidth is set via FILTER pin:
80 kHz typ. Bandwidth with 1 nF filter capacitor
Factory-trimmed for accuracy
Extremely stable output offset voltage
Near zero magnetic hysteresis
Typical total output error of ±1.5%
>25 kV/μs Common-Mode Transient Immunity
Small footprint, low-profile SO-8 package
Worldwide Safety Approval: UL, CSA:
Isolation Voltage 3 kV
RMS
, 1 minute
Applications
Low-power inverter current sensing
Motor phase and rail current sensing
Solar inverters
Chargers and Converters
Switching Power Supplies
CAUTION!
It is advised that normal static precautions be taken in handling and assembly of this component to prevent
damage and/or degradation which may be induced by ESD. The components featured in this data sheet are not
to be used in military or aerospace applications or environments.
Broadcom
ACHS-712x-DS101
February 28, 2018
ACHS-7121/7122/7123
Data Sheet
Fully Integrated, Hall Effect-Based Linear Current Sensor IC with 3 kV
RMS
Isolation and
Low-Resistance Current Conductor
Functional Diagram
I
P+
I
P+
I
P–
I
P–
1
2
3
4
8
7
6
5
V
DD
V
OUT
FILTER
GND
NOTE:
The connection of 1 μF bypass capacitor between pins 8 and 5 is recommended.
Pin Description
Pin
1
2
3
4
Pin Name
I
P+
I
P+
I
P–
I
P–
Description
Terminals for current being sampled; fused
internally
Terminals for current being sampled; fused
internally
Pin
8
7
6
5
Pin Name
V
DD
V
OUT
FILTER
GND
Description
Supply voltage relative to GND
Output Voltage
Filter pin to set bandwidth
Output side ground
Typical Application Circuit
A typical application circuit for the ACHS-7121/7122/7123 product series consists of a bypass capacitor and a filter capacitor
as additional external components. On the input side, pins 1 and 2 are shorted together and pins 3 and 4 shorted together.
The output voltage is directly measured from the V
OUT
pin.
5V
I
P+
I
P–
I
P+
I
P+
I
P–
I
P–
V
DD
V
OUT
FILTER
GND
C
BYPASS
OUTPUT
C
F
Broadcom
ACHS-712x-DS101
2
ACHS-7121/7122/7123
Data Sheet
Fully Integrated, Hall Effect-Based Linear Current Sensor IC with 3 kV
RMS
Isolation and
Low-Resistance Current Conductor
Ordering Information
Option
Part Number
ACHS-7121
ACHS-7122
ACHS-7123
Current Range
±10A
±20A
±30A
(RoHS)
Compliant
-000E
-500E
-000E
-500E
-000E
-500E
UL 3 kV
RMS
Package
SO-8
Surface Mount
X
X
X
X
X
X
X
X
X
Tape and Reel
1 min. rating
X
X
X
X
X
X
Quantity
100 per tube
1500 per reel
100 per tube
1500 per reel
100 per tube
1500 per reel
To order, choose a part number from the part number column and combine with the desired option from the option column
to form an order entry.
Example:
Select ACHS-7122-500E to order product of ±20A, surface-mount package in tape and reel packaging and
RoHS compliance. Contact your Broadcom sales representative or authorized distributor for information.
Option data sheets are available. Contact your Broadcom sales representative or authorized distributor for information.
Broadcom
ACHS-712x-DS101
3
ACHS-7121/7122/7123
Data Sheet
Fully Integrated, Hall Effect-Based Linear Current Sensor IC with 3 kV
RMS
Isolation and
Low-Resistance Current Conductor
Package Outline Drawing
ACHS-7121/7122/7123 SO-8 Package
0.457
(0.018)
8
Part Number
Datecode
RoHS
Compliance
Lot ID
1.27
(0.050
)
7
6
5
XXXX
YYWW
EEE
1
2
5.080
(0.200
3
+0.254
–0.127
+0.010
–0.005
3.937
–0.127
(0.155
+0.010
)
–0.005
+0.254
7.49
(0.295)
1.9 (0.075)
4
0.64 (0.025)
)
7°
0.254 ±0.050
(0.010 ±0.002)
0.800 ±0.127
(0.031 ±0.005)
1.908 ±0.127
(0.075 ±0.005)
0.381±0.127
(0.015 ±0.005)
0.203 ±0.100
(0.008 ±0.004)
6.000
–0.127
+0.010
(0.236
–0.005
)
+0.254
0° to 7°
Dimensions in millimeters (inches).
NOTE:
Lead Coplanarity = 0.100 mm (0.004 inches) max.
Floating lead protrusion = 0.254 mm (0.010 inches) max.
Mold Flash on each side = 0.127 mm (0.005 inches) max.
Recommended Pb-Free IR Profile
Recommended reflow condition as per JEDEC Standard, J-STD-020 (latest revision). Non-halide flux should be used.
Broadcom
ACHS-712x-DS101
4
ACHS-7121/7122/7123
Data Sheet
Fully Integrated, Hall Effect-Based Linear Current Sensor IC with 3 kV
RMS
Isolation and
Low-Resistance Current Conductor
Regulatory Information
The ACHS-7121/7122/7123 is approved by the following organizations:
UL/cUL
UL 1577, component recognition program up to V
ISO
= 3000V
RMS
. Approved under CSA Component Acceptance Notice #5.
Insulation and Safety Related Specifications
Parameter
Minimum External Air Gap (External
Clearance)
Minimum External Tracking (External
Creepage)
Minimum Internal Plastic Gap (Internal
Clearance)
Tracking Resistance (Comparative
Tracking Index)
Isolation Group
Symbol
L(101)
L(102)
—
Value
4.0
4.0
0.05
Unit
mm
mm
mm
Conditions
Measured from input terminals to output terminals,
shortest distance through air.
Measured from input terminals to output terminals,
shortest distance path along body.
Through insulation distance, conductor to conductor,
usually the direct distance between the primary input
conductor and detector IC.
DIN IEC 112/VDE 0303 Part 1.
Material Group (DIN VDE 0110, 1/89, Table 1).
CTI
—
>175
IIIa
V
—
Absolute Maximum Rating
Parameter
Storage Temperature
Ambient Operating Temperature
Junction Temperature
Primary Conductor Lead Temperature
Supply Voltages
Output Voltage
Output Current Source
Output Current Sink
Overcurrent Transient Tolerance
Input Power Dissipation
Output Power Dissipation
Symbol
T
S
T
A
T
J
T
L
V
DD
V
OUT
I
OUT(source)
I
OUT(sink)
I
P
P
IN
P
OUT
Min.
–55
–40
—
—
–0.5
–0.5
—
—
—
—
—
Max.
125
110
150
150
8.0
V
DD
+ 0.5
10
10
100
900
90
Unit
°C
°C
°C
°C
V
V
mA
mA
A
mW
mW
Test Conditions
—
—
—
Pins 1, 2, 3, or 4
—
—
T
A
= 25°C
T
A
= 25°C
1 pulse, 100 ms;
T
A
= 25°C
T
A
= 25°C
T
A
= 25°C
Broadcom
ACHS-712x-DS101
5
51mcu
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