ACS756SCA-100B-PFF-T - ALLEGRO MICROSYSTEMS

Application 1. The ACS756 outputs an analog signal, VOUT

, that

varies linearly with the uni- or bi-directional AC or DC primary

sampled current, IP

, within the range specified. CF is for optimal

noise management, with values that depend on the application.

ACS756

Description

The Allegro ACS756 family of current sensor ICs provides

economical and precise solutions for AC or DC current sensing

in industrial, automotive, commercial, and communications

systems. The device package allows for easy implementation by

the customer. Typical applications include motor control, load

detection and management, power supplies, and overcurrent

fault protection.

The device consists of a precision, low-offset linear Hall

circuit with a copper conduction path located near the die.

Applied current flowing through this copper conduction path

generates a magnetic field which 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 BiCMOS Hall IC, which is programmed

for accuracy at the factory.

The output of the device has a positive slope (>VCC

/ 2) when an

increasing current flows through the primary copper conduction

path (from terminal 4 to terminal 5), which is the path used

for current sampling. The internal resistance of this conductive

path is 130 μΩ typical, providing low power loss.

The thickness of the copper conductor allows survival of the

device at up to 5× overcurrent conditions. The terminals of the

ACS756-DS, Rev. 6

Features and Benefits

▪ Industry-leading noise performance through proprietary

amplifier and filter design techniques

▪ Total output error 0.8% at TA = 25°C

▪ Small package size, with easy mounting capability

▪ Monolithic Hall IC for high reliability

▪ Ultra-low power loss: 130 μΩ internal conductor resistance

▪ 3 kVRMS minimum isolation voltage from

pins 1-3 to pins 4-5

▪ 3.0 to 5.0 V, single supply operation

▪ 3 μs output rise time in response to step input current

▪ 20 or 40 mV/A output sensitivity

▪ Output voltage proportional to AC or DC currents

▪ Factory-trimmed for accuracy

▪ Extremely stable output offset voltage

▪ Nearly zero magnetic hysteresis

Fully Integrated, Hall Ef fect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

Continued on the next page…

Package: 5 pin package (suffix PFF)

Typical Application

+5 V

VOUT

CBYP

0.1 μF

IP+

IP–

GND

ACS756

VIOUT

VCC

Additional leadforms available for qualifying volumes

TÜV America

Certificate Number:

U8V 09 05 54214 021

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Selection Guide

Part Number1TOP

(°C)

Primary Sampled

Current , IP

(A) Packing2

ACS756SCA-050B-PFF-T –20 to 85 ±50

34 per tubeACS756SCA-100B-PFF-T –20 to 85 ±100

ACS756KCA-050B-PFF-T –40 to 125 ±50

1Additional leadform options available for qualified volumes

2Contact Allegro for additional packing options.

conductive path are electrically isolated from the signal leads (pins

1 through 3). This allows the ACS756 family of sensor ICs to be

used in applications requiring electrical isolation without the use of

opto-isolators or other costly isolation techniques.

The device is fully calibrated prior to shipment from the factory.

The ACS75x family is lead (Pb) free. All leads are plated with 100%

matte tin, and there is no Pb inside the package. The heavy gauge

leadframe is made of oxygen-free copper.

Description (continued)

Absolute Maximum Ratings

Characteristic Symbol Notes Rating Units

Forward Supply Voltage VCC 8V

Reverse Supply Voltage VRCC –0.5 V

Forward Output Voltage VIOUT 28 V

Reverse Output Voltage VRIOUT –0.5 V

Working Voltage for Reinforced Isolation VWORKING-R

Voltage applied between pins 1-3 and 4-5;

tested at 3000 VAC for 1 minute according to

UL standard 60950-1

353 VDC / Vpk

Working Voltage for Basic Isolation VWORKING-B

Voltage applied between pins 1-3 and 4-5;

tested at 3000 VAC for 1 minute according to

UL standard 60950-1

500 VDC / Vpk

Output Source Current IOUT(Source) VIOUT to GND 3 mA

Output Sink Current IOUT(Sink) VCC to VIOUT 1 mA

Nominal Operating Ambient Temperature TOP

Range K –40 to 125 ºC

Range S –20 to 85 ºC

Maximum Junction TJ(max) 165 ºC

Storage Temperature Tstg –65 to 165 ºC

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

IP+

IP–

VIOUT

GND

VCC

Terminal List Table

Number Name Description

1 VCC Device power supply terminal

2 GND Signal ground terminal

3 VIOUT Analog output signal

4 IP+ Terminal for current being sampled

5 IP– Terminal for current being sampled

Functional Block Diagram

Pin-out Diagram

Amp Out

VCC

+5 V

VIOUT

GND

Filter

Dynamic Offset

Cancellation

0.1 μF

IP–

IP+

Gain Temperature

Coefficient Offset

Trim Control

To all subcircuits

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

COMMON OPERATING CHARACTERISTICS1 over full range of TOP, and VCC = 5 V, unless otherwise specified

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Supply Voltage2VCC 3 5.0 5.5 V

Supply Current ICC VCC = 5.0 V, output open – 10 14 mA

Power On Time tPO TA = 25°C – 35 – s

Rise Time trIP = three-quarter scale of IP+, TA = 25°C, COUT = 0.47 nF – 3 – s

Internal Bandwidth3BWi–3 dB; IP is 10 A peak-to-peak; 100 pF from VIOUT to GND – 120 – kHz

Output Load Resistance RLOAD(MIN) VIOUT to GND 4.7 – – k

Output Load Capacitance CLOAD(MAX) VIOUT to GND – – 10 nF

Primary Conductor Resistance RPRIMARY TA = 25°C – 130 – 

Symmetry ESYM Over half-scale of Ip 98.5 100 101.5 %

Bidirectional 0 A Output VOUT(QBI) IP = 0 A, TA = 25°C – VCC/2 – V

Magnetic Offset Error IERROM IP = 0 A, after excursion of 100 A – ±0.23 – A

Ratiometry VRAT VCC = 4.5 to 5.5 V – 100 – %

Propagation Time tPROP TA = 25°C, COUT = 100 pF, – 1 – s

1Device is factory-trimmed at 5 V, for optimal accuracy.

2Devices are programmed for maximum accuracy at 5.0 V VCC levels. The device contains ratiometry circuits that accurately alter the 0 A Output Volt-

age and Sensitivity level of the device in proportion to the applied VCC level. However, as a result of minor nonlinearities in the ratiometry circuit ad-

ditional output error will result when VCC varies from the 5 V VCC level. Customers that plan to operate the device from a 3.3 V regulated supply should

contact their local Allegro sales representative regarding expected device accuracy levels under these bias conditions.

3Guaranteed by design.

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

X050 PERFORMANCE CHARACTERISTICS over Range S1: TOP = –20°C to 85°C, VCC

= 5 V, unless otherwise specified

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Primary Sampled Current IP–50 – 50 A

Sensitivity SensTA Half scale of IP applied for 5 ms, TA = 25°C – 40 – mV/A

SensTOP Half scale of IP applied for 5 ms 38.3 – 41.7 mV/A

Noise2VNOISE TA= 25°C, 10 nF on VIOUT pin to GND – 10 – mV

Nonlinearity ELIN(HT) Up to full scale of IP

, IP applied for 5 ms, TOP = 25°C to 85°C – 1 – 1 %

ELIN(LT) Up to full scale of IP

, IP applied for 5 ms, TOP = –20°C to 25°C – 1 – 1 %

Electrical Offset Voltage3

VOE(TA) IP = 0 A, TA = 25°C – ±2 – mV

VOE(TOP)HT IP = 0 A, TOP = 25°C to 85°C –30 – 30 mV

VOE(TOP)LT IP = 0 A, TOP = –20°C to 25°C –30 – 30 mV

Total Output Error4ETOT(HT) Over full scale of IP

, IP applied for 5 ms, TOP = 25°C to 85°C –5 – 5 %

ETOT(LT) Over full scale of IP

, IP applied for 5 ms, TOP = –20°C to 25°C –5 – 5 %

1Device may be operated at higher primary current levels, IP, and ambient temperatures, TOP, provided that the Maximum Junction Temperature,

TJ(max), is not exceeded.

26 noise voltage.

OE(TOP) drift is referred to ideal VOE = 2.5 V at 0 A.

4Percentage of IP, with IP = 25 A. Output filtered.

X050 PERFORMANCE CHARACTERISTICS over Range K1: TOP = –40°C to 125°C, VCC

= 5 V, unless otherwise specified

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Primary Sampled Current IP–50 – 50 A

Sensitivity SensTA Half scale of IP applied for 5 ms, TA = 25°C – 40 – mV/A

SensTOP Half scale of IP applied for 5 ms 37.2 – 42.8 mV/A

Noise2VNOISE TA= 25°C, 10 nF on VIOUT pin to GND – 10 – mV

Nonlinearity ELIN(HT) Up to full scale of IP

, IP applied for 5 ms, TOP = 25°C to 125°C – 1 – 1 %

ELIN(LT) Up to full scale of IP

, IP applied for 5 ms, TOP = –40°C to 25°C – 1.8 – 1.8 %

Electrical Offset Voltage3

VOE(TA) IP = 0 A, TA = 25°C – ±2 – mV

VOE(TOP)HT IP = 0 A, TOP = 25°C to 125°C –30 – 30 mV

VOE(TOP)LT IP = 0 A, TOP = –40°C to 25°C –60 – 60 mV

Total Output Error4ETOT(HT) Over full scale of IP

, IP applied for 5 ms, TOP = 25°C to 125°C –7.5 – 7.5 %

ETOT(LT) Over full scale of IP

, IP applied for 5 ms, TOP = –40°C to 25°C –7.5 – 7.5 %

1Device may be operated at higher primary current levels, IP, and ambient temperatures, TOP, provided that the Maximum Junction Temperature,

TJ(max), is not exceeded.

26 noise voltage.

OE(TOP) drift is referred to ideal VOE = 2.5 V at 0 A.

4Percentage of IP, with IP = 25 A. Output filtered.

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

X100 PERFORMANCE CHARACTERISTICS over Range S1: TOP = –20°C to 85°C, VCC

= 5 V, unless otherwise specified

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Primary Sampled Current IP–100 – 100 A

Sensitivity SensTA Half scale of IP applied for 5 ms, TA = 25°C – 20 – mV/A

SensTOP Half scale of IP applied for 5 ms 18.2 – 21.8 mV/A

Noise2VNOISE TA= 25°C, 10 nF on VIOUT pin to GND – 6 – mV

Nonlinearity ELIN(HT) Up to full scale of IP

, IP applied for 5 ms, TOP = 25°C to 85°C – 1.75 – 1.75 %

ELIN(LT) Up to full scale of IP

, IP applied for 5 ms, TOP = –20°C to 25°C – 1 – 1 %

Electrical Offset Voltage3

VOE(TA) IP = 0 A, TA = 25°C – ±2 – mV

VOE(TOP)HT IP = 0 A, TOP = 25°C to 85°C –30 – 30 mV

VOE(TOP)LT IP = 0 A, TOP = –20°C to 25°C –30 – 30 mV

Total Output Error4ETOT(HT) Over full scale of IP

, IP applied for 5 ms, TOP = 25°C to 85°C –8 – 8 %

ETOT(LT) Over full scale of IP

, IP applied for 5 ms, TOP = –20°C to 25°C –7 – 7 %

1Device may be operated at higher primary current levels, IP, and ambient temperatures, TOP, provided that the Maximum Junction Temperature,

TJ(max), is not exceeded.

26 noise voltage.

OE(TOP) drift is referred to ideal VOE = 2.5 V at 0 A.

4Percentage of IP, with IP = 25 A. Output filtered.

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

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

half-scale current of the device.

Noise (VNOISE). 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.

Nonlinearity (ELIN). The degree to which the voltage output

from the IC varies in direct proportion to the primary current

through its half-scale amplitude. Nonlinearity in the output can be

attributed to the saturation of the flux concentrator approaching

the half-scale current. The following equation is used to derive

the linearity:

100 1–

[{

VIOUT_half-scale amperes – VIOUT(Q)

Δ gain × % sat ( )

2 (VIOUT_quarter-scale amperes – VIOUT(Q) )

where

∆ gain = the gain variation as a function of temperature

changes from 25ºC,

% sat = the percentage of saturation of the flux concentra-

tor, which becomes significant as the current being sampled

approaches half-scale ±IP , and

VIOUT_half-scale amperes = the output voltage (V) when the

sampled current approximates half-scale ±IP .

Symmetry (ESYM). The degree to which the absolute voltage

output from the IC varies in proportion to either a positive or

negative half-scale primary current. The following equation is

used to derive symmetry:

100

VIOUT_+ half-scale amperes – VIOUT(Q)

VIOUT(Q) – VIOUT_–half-scale amperes



Ratiometry. The device features a ratiometric output. This

means that the quiescent voltage output, VIOUTQ, and the mag-

netic sensitivity, Sens, are proportional to the supply voltage, VCC.

The ratiometric change (%) in the quiescent voltage output is

defined as:

5 V

IOUTQ(V

)

IOUTQ(5V)

IOUTQ($V)

=s%

and the ratiometric change (%) in sensitivity is defined as:

VCC 5 V

=s%

$Sens($V

Sens(VCCSens(V

Quiescent output voltage (VIOUT(Q)). The output of the device

when the primary current is zero. For a unipolar supply voltage,

it nominally remains at VCC ⁄ 2. Thus, VCC = 5 V translates into

VIOUT(Q) = 2.5 V. Variation in VOUT(Q) can be attributed to the res-

olution of the Allegro linear IC quiescent voltage trim, magnetic

hysteresis, and thermal drift.

Electrical offset voltage (VOE). The deviation of the device out-

put from its ideal quiescent value of VCC ⁄ 2 due to nonmagnetic

causes.

Magnetic offset error (IERROM). The magnetic offset is due to

the residual magnetism (remnant field) of the core material. The

magnetic offset error is highest when the magnetic circuit has

been saturated, usually when the device has been subjected to a

full-scale or high-current overload condition. The magnetic offset

is largely dependent on the material used as a flux concentrator.

The larger magnetic offsets are observed at the lower operating

temperatures.

Total Output Error (ETOT). The maximum deviation of the

actual output from its ideal value, also referred to as accuracy,

illustrated graphically in the output voltage versus current chart

on the following page.

ETOT is divided into four areas:

 0 A at 25°C. Accuracy at the zero current flow at 25°C, with-

out the effects of temperature.

 0 A over Δ temperature. Accuracy at the zero current flow

including temperature effects.

 Half-scale current at 25°C. Accuracy at the the half-scale current

at 25°C, without the effects of temperature.

 Half-scale current over Δ temperature. Accuracy at the half-

scale current flow including temperature effects.

Definitions of Accuracy Characteristics

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Output Voltage versus Sampled Current

Total Output Error at 0 A and at Half-Scale Current

Increasing VIOUT

(V)

+IP (A)

Accuracy

25°C Only

Accuracy

25°C Only

Accuracy

25°C Only

Accuracy

0 A

vrOe $Temp erature

Average

VIOUT

–IP (A)

vrOe $Temp erature

Decreasing VIOUT

(V)

IP(min)

IP(max)

Half Scale

Definitions of Dynamic Response Characteristics

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.

Primary Current

Transducer Output

I (%)

Propagation Time, tPROP

Primary Current

Transducer Output

I (%)

Rise Time, trt

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.

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.

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

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.

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.

Chopper Stabilization Technique

Amp

Regulator

Clock/Logic

Hall Element

Sample and

Hold

Low-Pass

Filter

Concept of Chopper Stabilization Technique

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Package CA, 5-pin package, leadform PFF

1.91

321.4

0.5

0.8

1.5

0.5

Perimeter through-holes recommended

1º±2°

5º±5°

14.0±0.2

17.5±0.2

4.0±0.2

3.0±0.2

2.9±0.2

3.5±0.2

10.00±0.10

13.00±0.10

0.51±0.10

4.40±0.10

7.00±0.10

1.9±0.2

1.50±0.10

Branding scale and appearance at supplier discretion

Dambar removal intrusion For Reference Only; not for tooling use (reference DWG-9111, DWG-9110)

Dimensions in millimeters

Dimensions exclusive of mold flash, gate burrs, and dambar protrusions

Exact case and lead configuration at supplier discretion within limits shown

Standard Branding Reference View

N = Device part number

T = Temperature code

A = Amperage range

L = Lot number

Y = Last two digits of year of manufacture

W = Week of manufacture

= Supplier emblem

Branded

Face

0.381+0.060

–0.030

NNNNNNN

TTT - AAA

LLLLLLL

YYWW

PCB Layout Reference View

Fully Integrated, Hall Effect-Based Linear Current Sensor IC

with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS756

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Revision History

Revision Revision Date Description of Revision

Rev. 6 March 25, 2011 Augment VCC specification

The products described herein are protected by U.S. patents: 6,781,359; and 7,265,531.

Allegro MicroSystems, Inc. reserves the right to make, from time to time, such de par tures from the detail spec i fi ca tions as may be required to per-

mit improvements in the per for mance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the

information being relied upon is current.

Allegro’s products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the

failure of that life support device or system, or to affect the safety or effectiveness of that device or system.

The in for ma tion in clud ed herein is believed to be ac cu rate and reliable. How ev er, Allegro MicroSystems, Inc. assumes no re spon si bil i ty for its use;

nor for any in fringe ment of patents or other rights of third parties which may result from its use.

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