ACS712芯片引脚定义引脚图及功能IC贸易商引脚图技术参数-中国IC网-芯三七

ACS712

Fully Integrated, Hall Effect-Based Linear Current Sensor

with 2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

Features and Benefits

Description

The Allegro^®ACS712 provides economical and precise

solutionsforACorDCcurrentsensinginindustrial,automotive,

commercial, and communications systems. The device

package allows for easy implementation by the customer.

Typical applications include motor control, load detection and

management, switched-mode power supplies, and overcurrent

fault protection.

▪

Low-noise analog signal path

Device bandwidth is set via the new FILTER pin

5 μs output rise time in response to step input current

50 kHz bandwidth

Total output error 1.5% at T_A= 25°C, and 4% at –40°C to 85°C

Small footprint, low-profile SOIC8 package

1.2 mΩ internal conductor resistance

2.1 kV_RMSminimum isolation voltage from pins 1-4 to pins 5-8

5.0 V, single supply operation

66 to 185 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

Ratiometric output from supply voltage

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

sensor 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 which is sensed

by the integrated Hall IC and converted 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 after packaging.

Package: 8 pin SOIC (suffix LC)

The output of the device has a positive slope (>V_IOUT(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 sensing. The internal resistance of

this conductive path is 1.2 mΩ typical, providing low power

Continued on the next page…

Approximate Scale 1:1

Typical Application

+5 V

8

7

1

2

VCC

IP+

V_OUT

C

VIOUT

0.^B1^YPμF

I_P

ACS712

6

5

3

4

FILTER

IP–

C

1^FnF

GND

Application 1. The ACS712 outputs an analog signal, V_OUT

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

primary sensed current, I_P, within the range specified. C_F

is recommended for noise management, with values that

depend on the application.

.

ACS712-DS, Rev.1

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

Description (continued)

TheACS712 is provided in a small, surface mount SOIC8 package.

The leadframe is plated with 100% matte tin, which is compatible

withstandardlead(Pb)freeprintedcircuitboardassemblyprocesses.

Internally,thedeviceisPb-free,exceptforflip-chiphigh-temperature

Pb-based solder balls, currently exempt from RoHS. The device is

fully calibrated prior to shipment from the factory.

loss. The thickness of the copper conductor allows survival of

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

the conductive path are electrically isolated from the sensor leads

(pins 5 through 8). This allows the ACS712 current sensor to be

used in applications requiring electrical isolation without the use

of opto-isolators or other costly isolation techniques.

Selection Guide

T_OP

(°C)

Optimized Range, I_PSensitivity, Sens

Part Number

Packing*

(A)

(Typ) (mV/A)

ACS712ELCTR-05B-T Tape and reel, 3000 pieces/reel

ACS712ELCTR-20A-T Tape and reel, 3000 pieces/reel

ACS712ELCTR-30A-T Tape and reel, 3000 pieces/reel

*Contact Allegro for additional packing options.

–40 to 85

±5

185

100

66

±20

±30

Absolute Maximum Ratings

Characteristic

Symbol

V_CC

Notes

Rating

8

Units

V

Supply Voltage

Reverse Supply Voltage

Output Voltage

V_RCC

–0.1

8

V

V_IOUT

V

Reverse Output Voltage

Output Current Source

Output Current Sink

V_RIOUT

I_IOUT(Source)

I_IOUT(Sink)

–0.1

3

V

mA

10

100 total pulses, 250 ms duration each, applied

at a rate of 1 pulse every 100 seconds.

Overcurrent Transient Tolerance

I_P

60

A

Maximum Transient Sensed Current

Nominal Operating Ambient Temperature

Maximum Junction

I_R(max)

T_A

Junction Temperature, T_J< T_J(max)

Range E

60

–40 to 85

165

A

ºC

T_J(max)

T_stg

Storage Temperature

–65 to 170

ºC

Parameter

Fire and Electric Shock

Specification

TÜV America

CAN/CSA-C22.2 No. 60950-1-03

UL 60950-1:2003

Certificate Number:

U8V 06 05 54214 010

EN 60950-1:2001

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

2

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

Functional Block Diagram

+5 V

VCC

(Pin 8)

Hall Current

Drive

IP+

Sense Temperature

Coefficient Trim

(Pin 1)

IP+

(Pin 2)

Signal

VIOUT

(Pin 7)

Recovery

R

F(INT)

IP−

(Pin 3)

Sense

Trim

IP−

0 Ampere

Offset Adjust

(Pin 4)

GND

(Pin 5)

FILTER

(Pin 6)

Pin-out Diagram

IP+

IP–

1

2

3

4

8

7

6

5

VCC

VIOUT

FILTER

GND

Terminal List Table

Number

Name

Description

1 and 2

IP+

Terminals for current being sensed; fused internally

Signal ground terminal

3 and 4

IP–

5

6

7

8

GND

FILTER

VIOUT

VCC

Terminal for external capacitor that sets bandwidth

Analog output signal

Device power supply terminal

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

3

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

COMMON OPERATING CHARACTERISTICS¹over full range of T_OP, C_F= 1 nF, and V_CC= 5 V, unless otherwise specified

Characteristic

Symbol

Test Conditions

Min.

Typ.

Max.

Units

ELECTRICAL CHARACTERISTICS

Supply Voltage

V_CC

4.5

6

5.0

8

5.5

11

–

V

mA

V

Supply Current

I_CC

V_Z

V_CC= 5.0 V, output open

I_CC= 11 mA, T_A= 25°C

I_IOUT= 1.2 mA, T_A=25°C

VIOUT to GND

Output Zener Clamp Voltage

Output Resistance

6

8.3

1

R_IOUT

C_LOAD

R_LOAD

–

2

Ω

Output Capacitance Load

Output Resistive Load

–

10

–

nF

kΩ

mΩ

V

VIOUT to GND

4.7

–

Primary Conductor Resistance R_PRIMARYT_A= 25°C

1.2

–

RMS Isolation Voltage

DC Isolation Voltage

Propagation Time

Response Time

Rise Time

V_ISORMSPins 1-4 and 5-8; 60 Hz, 1 minute, T_A=25°C

2100

–

V_ISODC

t_PROP

Pins 1-4 and 5-8; 1 minute, T_A=25°C

I_P= I_P(max), T_A= 25°C, C_OUT= open

5000

3

–

V

–

μs

kHz

%

t_RESPONSEI_P= I_P(max), T_A= 25°C, C_OUT= open

–

7

–

t_r

f

I_P= I_P(max), T_A= 25°C, C_OUT= open

–3 dB, T_A= 25°C; I_Pis 10 A peak-to-peak

Over full range of I_P

–

5

–

Frequency Bandwidth

Nonlinearity

50

–

E_LIN

E_SYM

±1

100

±1.5

102

Symmetry

Over full range of I_P

98

%

V_CC

0.5

×

Zero Current Output Voltage

Magnetic Offset Error

V_IOUT(Q)Bidirectional; I_P= 0 A, T_A= 25°C

V_ERROMI_P= 0 A, after excursion of 5 A

V_CH

–

V

0

mV

V_CC

0.9375

×

Typ.–110

Typ.+110

Clamping Voltage

Power-On Time

V_CC

0.0625

×

V_CL

Typ.–110

Typ.+110

mV

Output reaches 90% of steady-state level, T_J=25°C, 20 A present

on leadframe

t_PO

–

35

–

ꢀs

Magnetic Coupling²

12

G/A

Internal Filter Resistance³

R_F(INT)

1.7

kꢁ

¹Device may be operated at higher primary current levels, I_P, and ambient, T_A, and internal leadframe temperatures, T_OP, provided that the Maximum

Junction Temperature, T_J(max), is not exceeded.

²1G = 0.1 mT.

³R_F(INT)forms an RC circuit via the FILTER pin.

COMMON THERMAL CHARACTERISTICS¹

Min.

–40

Typ.

–

Max.

85

Units

°C

Operating Internal Leadframe Temperature

T_OPE range

Value

5

Units

°C/W

Junction-to-Lead Thermal Resistance²

Junction-to-Ambient Thermal Resistance

R_θJLMounted on the Allegro ASEK 712 evaluation board

Mounted on the Allegro 85-0322 evaluation board, includes the power con-

sumed by the board

R_θJA

23

°C/W

¹Additional thermal information is available on the Allegro website.

²The Allegro evaluation board has 1500 mm²of 2 oz. copper on each side, connected to pins 1 and 2, and to pins 3 and 4, with thermal vias connect-

ing the layers. Performance values include the power consumed by the PCB. Further details on the board are available from the Frequently Asked

Questions document on our website. Further information about board design and thermal performance also can be found in the Applications Informa-

tion section of this datasheet.

Allegro MicroSystems, Inc.

4

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

x05A PERFORMANCE CHARACTERISTICS T_OP= –40°C to 85°C¹, C_F= 1 nF, and V_CC= 5 V, unless otherwise specified

Characteristic

Symbol

Test Conditions

Min.

Typ.

Max.

5

Units

A

Optimized Accuracy Range

I_P

–5

–

Sens_TA

Over full range of I_P,T_A= 25°C

–

185

–

mV/A

Sensitivity²

Noise

Sens_TOPOver full range of I_P

178

193

Peak-to-peak, T_A= 25°C, 185 mV/A programmed Sensitivity,

C_F=4.7 nF, C_OUT= open, 20 kHz bandwidth

–

45

20

75

–

mV

Peak-to-peak, T_A= 25°C, 185 mV/A programmed Sensitivity,

C_F= 47 nF, C_OUT= open, 2 kHz bandwidth

V_NOISE(PP)

Peak-to-peak, T_A= 25°C, 185 mV/A programmed Sensitivity,

C_F= 1 nF, C_OUT= open, 50 kHz bandwidth

Electrical Offset Voltage

Total Output Error³

V_OE

I_P= 0 A

–40

–

40

–

mV

%

E_TOT

I_P=±5 A, T_A= 25°C

±1.5

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

_J(max), is not exceeded.

T

²At –40°C Sensitivity may shift as much 9% outside of the datasheet limits.

³Percentage of I_P, with I_P= 5 A. Output filtered.

x20A PERFORMANCE CHARACTERISTICS T_OP= –40°C to 85°C¹, C_F= 1 nF, and V_CC= 5 V, unless otherwise specified

Characteristic

Symbol

Test Conditions

Min.

–20

–

Typ.

Max.

20

Units

A

Optimized Accuracy Range

I_P

–

Sens_TA

Over full range of I_P,T_A= 25°C

100

–

mV/A

Sensitivity²

Noise

Sens_TOPOver full range of I_P

97

103

Peak-to-peak, T_A= 25°C, 100 mV/A programmed Sensitivity,

C_F=4.7 nF, C_OUT= open, 20 kHz bandwidth

–

24

10

40

–

mV

Peak-to-peak, T_A= 25°C, 100 mV/A programmed Sensitivity,

C_F= 47 nF, C_OUT= open, 2 kHz bandwidth

V_NOISE(PP)

Peak-to-peak, T_A= 25°C, 100 mV/A programmed Sensitivity,

C_F= 1 nF, C_OUT= open, 50 kHz bandwidth

Electrical Offset Voltage

Total Output Error³

V_OE

I_P= 0 A

–30

–

30

–

mV

%

E_TOT

I_P=±20 A, T_A= 25°C

±1.5

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

T_J(max), is not exceeded.

²At –40°C Sensitivity may shift as much 9% outside of the datasheet limits.

³Percentage of I_P, with I_P= 20 A. Output filtered.

x30A PERFORMANCE CHARACTERISTICS T_OP= –40°C to 85°C¹, C_F= 1 nF, and V_CC= 5 V, unless otherwise specified

Characteristic

Symbol

Test Conditions

Min.

–30

–

Typ.

Max.

30

Units

A

Optimized Accuracy Range

I_P

–

Sens_TA

Over full range of I_P, T_A= 25°C

66

–

mV/A

Sensitivity²

Noise

Sens_TOPOver full range of I_P

64

68

Peak-to-peak, T_A= 25°C, 66 mV/A programmed Sensitivity,

C_F=4.7 nF, C_OUT= open, 20 kHz bandwidth

–

20

7

–

mV

Peak-to-peak, T_A= 25°C, 66 mV/A programmed Sensitivity,

C_F= 47 nF, C_OUT= open, 2 kHz bandwidth

V_NOISE(PP)

Peak-to-peak, T_A= 25°C, 66 mV/A programmed Sensitivity,

C_F= 1 nF, C_OUT= open, 50 kHz bandwidth

35

Electrical Offset Voltage

Total Output Error³

V_OE

I_P= 0 A

–30

–

30

–

mV

%

E_TOT

I_P= ±30 A, T_A= 25°C

±1.5

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

T_J(max), is not exceeded.

²At –40°C Sensitivity may shift as much 9% outside of the datasheet limits.

³Percentage of I_P, with I_P= 30 A. Output filtered.

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

5

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

Characteristic Performance

I_P= 5 A, Sens = 185 mV/A unless otherwise specified

Mean Supply Current versus Ambient Temperature

Supply Current versus Supply Voltage

V_CC= 5 V

10.5

10.0

9.5

9.0

8.5

8.0

7.5

7.0

6.5

10.3

10.1

9.9

9.7

9.5

9.3

9.1

8.9

8.7

8.5

6.0

-50

4.5 4.6 4.7 4.8 4.9

5

5.1 5.2 5.3 5.4 5.5

0

50

100

_A(°C)

150

200

V

_CC(V)

T

Magnetic Offset versus Ambient Temperature

Nonlinearity versus Ambient Temperature

I_P= 10 A

2.0

2.00

1.75

1.50

1.25

1.00

0.75

0.50

0.25

0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

-50

0

50

100

T_A(°C)

150

200

-50

0

50

100

T_A(°C)

150

200

Mean Total Output Error versus Ambient Temperature

I_P= 10 A

15.0

10.0

5.0

0.0

-5.0

-10.0

-15.0

-50

0

50

100

T_A(°C)

150

200

Output Voltage versus Sensed Current

Sensitivity versus Sensed Current

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

188.0

186.0

184.0

182.0

180.0

178.0

176.0

T_A(°C)

150

85

25

-40

25

-40

-10 -8 -6 -4 -2

0

2

4

6

8

10

-10 -8 -6 -4 -2

0

2

4

6

8

10

Ip (A)

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

6

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

Characteristic Performance

I_P= 30 A, Sens = 66 mV/A unless otherwise specified

Mean Supply Current versus Ambient Temperature

Supply Current versus Supply Voltage

V_CC= 5 V

10.5

10.0

9.5

9.0

8.5

8.0

7.5

7.0

6.5

10.3

10.1

9.9

9.7

9.5

9.3

9.1

8.9

8.7

8.5

6.0

-50

4.5 4.6 4.7 4.8 4.9

5

5.1 5.2 5.3 5.4 5.5

0

50

100

T_A(°C)

150

200

V

_CC(V)

Magnetic Offset Current versus Ambient Temperature

Nonlinearity versus Ambient Temperature

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

1.00

0.80

0.60

0.40

0.20

0

-50

0

50

100

T_A(°C)

150

200

-50

0

50

100

T_A(°C)

150

200

Mean Total Output Error versus Ambient Temperature

5.0

4.0

3.0

2.0

1.0

0.0

-1.0

-2.0

-3.0

-4.0

-5.0

-50

0

50

100

T_A(°C)

150

200

Output Voltage versus Sensed Current

Sensitivity versus Sensed Current

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

75.0

70.0

65.0

60.0

55.0

50.0

T_A(°C)

150

85

25

-40

25

-40

-30

-20

-10

0

10

20

30

-30

-20

-10

0

10

20

30

Ip (A)

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

7

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

Definitions of Accuracy Characteristics

Sensitivity (Sens). The change in sensor output in response to a

1A 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

full-scale current of the device.

Accuracy is divided into four areas:

• 0 A at 25°C. Accuracy of sensing zero current flow at 25°C,

without the effects of temperature.

• 0 A over Δ temperature. Accuracy of sensing zero current

flow including temperature effects.

• Full-scale current at 25°C. Accuracy of sensing the full-scale

current at 25°C, without the effects of temperature.

Noise (V_NOISE). The product of the linear IC amplifier gain

(mV/G) and the noise floor for the Allegro Hall effect linear IC

(≈1 G). 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.

• Full-scale current over Δ temperature. Accuracy of sensing full-

scale current flow including temperature effects.

Ratiometry. The ratiometric feature means that its 0 A output,

V_IOUT(Q), (nominally equal to V_CC/2) and sensitivity, Sens, are

Linearity (E_LIN). The degree to which the voltage output from

the sensor varies in direct proportion to the primary current

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

attributed to the saturation of the flux concentrator approaching

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

linearity:

proportional to its supply voltage, V_CC.The following formula is

used to derive the ratiometric change in 0 A output voltage,

ΔV_IOUT(Q)RAT(%).

V

_IOUT(Q)VCC/ V_IOUT(Q)5V

100

V_CC

/

5 V





V

– V_IOUT(Q)

⁾[ {

Δ gain × % sat (

IOUT_full-scale amperes

2 (V_{IOUT_half-scale amperes}– V_IOUT(Q)

100

1–

The ratiometric change in sensitivity, ΔSens_RAT(%), is defined as:

{

[

)

Sens_VCC/ Sens_5V

where V_{IOUT_full-scale amperes}= the output voltage (V) when the

sensed current approximates full-scale ±I_P.

100

V_CC

/

5 V

‰

ꢀ

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

output from the sensor varies in proportion to either a positive

or negative full-scale primary current. The following formula is

used to derive symmetry:

Output Voltage versus Sensed Current

Accuracy at 0 A and at Full-Scale Current

Increasing V_IOUT(V)

Accuracy

Over $Temp erature

V_{IOUT_+ full-scale amperes}– V_IOUT(Q)

100

V

_IOUT(Q)– V_{IOUT_–full-scale amperes}

Accuracy





25°C Only

Quiescent output voltage (V_IOUT(Q)). The output of the sensor

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

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

V_IOUT(Q)= 2.5 V. Variation in V_IOUT(Q)can be attributed to the

resolution of the Allegro linear IC quiescent voltage trim and

thermal drift.

Average

V

IOUT

Accuracy

Over $Temp erature

Accuracy

25°C Only

I_P(min)

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

put from its ideal quiescent value of V_CC/ 2 due to nonmagnetic

causes. To convert this voltage to amperes, divide by the device

sensitivity, Sens.

–I_P(A)

+I_P(A)

Full Scale

I

_P(max)

0 A

Accuracy (E_TOT). The accuracy represents the maximum devia-

tion of the actual output from its ideal value. This is also known

as the total ouput error. The accuracy is illustrated graphically in

the output voltage versus current chart at right.

Accuracy

25°C Only

Accuracy

Over $Temp erature

Decreasing V_IOUT(V)

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

8

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

Definitions of Dynamic Response Characteristics

Primary Current

I (%)

90

Propagation delay (t_PROP). The time required for the sensor

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.

Transducer Output

0

t

Propagation Time, t_PROP

Primary Current

I (%)

90

Response time (t_RESPONSE). The time interval between

a) when the primary current signal reaches 90% of its final

value, and b) when the sensor reaches 90% of its output

corresponding to the applied current.

Transducer Output

0

t

Response Time, t

Primary Current

RESPONSE

Rise time (t_r). The time interval between a) when the sensor

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 current sensor, in which ƒ(–3 dB) =

0.35/t_r. Both t_rand t_RESPONSEare detrimentally affected by eddy

current losses observed in the conductive IC ground plane.

I (%)

90

Transducer Output

10

0

t

Rise Time, t

r

Step Response

T_A=25°C

Power on Time versus External Filter Capacitance

200

180

160

140

120

100

80

I_P=5 A

I_P=0 A

60

40

20

0

Output (mV)

0

10

20

30

40

50

C

_F(nF)

Noise vs. Filter Cap

Noise versus External Filter Capacitance

15 A

10000

1000

100

Excitation Signal

10

1

0.01

0.1

1

10

100

1000

C_F(nF)

Rise Time versus External Filter Capacitance

C_F(nF)

t_r(μs)

400

350

300

250

200

150

0

1200

0

1

4.7

10

22

47

100

220

470

6.6

7.7

17.4

32.1

68.2

88.2

291.3

623.0

1120.0

1000

800

600

400

200

0

Expanded in chart at right

}

0

100

200

300

400

500

0

50

75

100

125

150

C_F(nF)

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

9

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

Chopper Stabilization Technique

Chopper Stabilization is an innovative circuit technique that is

This technique is made possible through the use of a BiCMOS

used to minimize the offset voltage of a Hall element and an asso- process that allows the use of low-offset and low-noise amplifiers

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 suppressed

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 tempera-

ture 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.

in combination with high-density logic integration and sample

and hold circuits.

Regulator

Clock/Logic

Low-Pass

Filter

Hall Element

Amp

Concept of Chopper Stabilization Technique

Typical Applications

+5 V

V_PEAK

C_BYP

0.1 μF

R1

C_BYP

0.1 μF

C2

100 kΩ

0.1 μF

V_RESET

R4

Q1

2N7002

10 kΩ

R2

C_OUT

8

7

100 kΩ

LM321

4

1

3

1

+

–

VCC

5

2

0.1 μF

8

7

IP+

V_OUT

1

2

VCC

V_OUT

+

–

IP+

2

VIOUT

IP+

VIOUT

R_F

10 kΩ

I_P

R_F

1 kΩ

ACS712

U1

D1

R1

1 MΩ

C_F

C1

I_P

ACS712

6

5

LT1178 1N914

3

4

1000 pF

FILTER

R3

6

5

IP–

3

4

FILTER

3.3 kΩ

IP–

C_F

0.01 μF

1 nF

GND

C1

R3

GND

R2

33 kΩ

0.1 μF

330 kΩ

Application 3. This configuration increases gain to 610 mV/A

(tested using the ACS712ELC-05A).

Application 2. Peak Detecting Circuit

+5 V

C_BYP

0.1 μF

R1

33 kΩ

C_BYP

0.1 μF

R_PU

R2

100 kΩ

8

7

8

1

2

VCC

1

D1

VCC

IP+

V_OUT

1N4448W

4

3

V_OUT

7

5

2

A-to-D

Converter

VIOUT

–

+

Fault

VIOUT

IP+

1

R_F

I_P

ACS712

I_P

2 kΩ

U1

R1

10 kΩ

C_F

1 nF

6

5

3

4

C1

6

5

LMV7235

FILTER

3

4

IP–

FILTER

GND

C_F

IP–

1 nF

GND

D1

1N914

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.

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.

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

10

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

Improving Sensing System Accuracy Using the FILTER Pin

In low-frequency sensing applications, it is often advantageous

to add a simple RC filter to the output of the sensor. Such a low-

pass filter improves the signal-to-noise ratio, and therefore the

resolution, of the sensor output signal. However, the addition of

an RC filter to the output of a sensor IC can result in undesirable

sensor output attenuation — even for dc signals.

temperature. Therefore, signal attenuation will vary as a function

of temperature. Note that, in many cases, the input impedance,

R_INTFC, of a typical analog-to-digital converter (ADC) can be as

low as 10 kꢀ.

The ACS712 contains an internal resistor, a FILTER pin connec-

tion to the printed circuit board, and an internal buffer amplifier.

With this circuit architecture, users can implement a simple

RC filter via the addition of a capacitor, C_F(see Application 7)

from the FILTER pin to ground. The buffer amplifier inside of

the ACS712 (located after the internal resistor and FILTER pin

connection) eliminates the attenuation caused by the resistive

divider effect described in the equation for ∆V_ATT. Therefore, the

ACS712 device is ideal for use in high-accuracy applications

that cannot afford the signal attenuation associated with the use

of an external RC low-pass filter.

Signal attenuation, ∆V_ATT, is a result of the resistive divider

effect between the resistance of the external filter, R_F(see

Application 6), and the input impedance and resistance of the

customer interface circuit, R_INTFC. The transfer function of this

resistive divider is given by:

R_INTFC

⎛

⎞

.

∆V_ATT

V

⎜

=

IOUT

⎟

R_F+ R_INTFC

⎝

⎠

Even if R_Fand R_INTFCare designed to match, the two individual

resistance values will most likely drift by different amounts over

+5 V

Pin 3 Pin 4

VCC

Pin 8

IP–

Allegro ACS706

Application 6. When a low pass filter is constructed

externally to a standard Hall effect device, a resistive

divider may exist between the filter resistor, R_F,and

the resistance of the customer interface circuit, R_INTFC

This resistive divider will cause excessive attenuation,

Voltage

Regulator

To all subcircuits

.

VIOUT

Pin 7

Resistive Divider

Input

R_F

Amp

Out

Application

Interface

Circuit

as given by the transfer function for ∆V_ATT

.

N.C.

Pin 6

0.1 MF

Low Pass Filter

Temperature

Coefficient

Gain

Offset

C_F

1 nF

R_INTFC

Trim Control

GND

Pin 5

IP+

Pin 1 Pin 2

IP+

+5 V

VCC

Pin 8

Allegro ACS712

Application 7. Using the FILTER pin

provided on the ACS712 eliminates the

attenuation effects of the resistor divider

between R_Fand R_INTFC, shown in Appli-

cation 6.

Hall Current

Drive

IP+

Sense Temperature

Coefficient Trim

Pin 1

IP+

Pin 2

Buffer Amplifier

and Resistor

Signal

Recovery

VIOUT

Pin 7

Input

Application

Interface

Circuit

IP–

Pin 3

Sense

Trim

IP–

Pin 4

0 Ampere

Offset Adjust

R_INTFC

GND

Pin 5

FILTER

Pin 6

C_F

1 nF

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

11

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

6.20 .244

5.80 .228

Package LC, 8-pin SOIC

0.25 [.010] M B M

5.00 .197

4.80 .189

8º

0º

A

B

8

0.25 .010

0.17 .007

Preliminary dimensions, for reference only

Dimensions in millimeters

U.S. Customary dimensions (in.) in brackets, for reference only

4.00 .157

3.80 .150

(reference JEDEC MS-012 AA)

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

Exact case and lead configuration at supplier discretion within limits shown

Terminal #1 mark area

1.27 .050

0.40 .016

A

1

2

0.25 .010

C

8X

SEATING PLANE

GAUGE PLANE

SEATING

PLANE

0.10 [.004]

C

0.51 .020

0.31 .012

0.25 [.010] M

1.75 .069

1.35 .053

8X

C A B

0.25 .010

0.10 .004

1.27 .050

1

2

3

4

8

7

6

5

Package Branding

Two alternative patterns are used

ACS

712

T

Allegro Current Sensor

Device family number

ACS

712

T

Allegro Current Sensor

Device family number

Indicator of 100% matte tin leadframe plating

Operating ambient temperature range code

Package type designator

Indicator of 100% matte tin leadframe plating

Operating ambient temperature range code

Package type designator

ACS712T

RLCPPP

L...L

ACS712T

RLCPPP

YYWWA

R

LC

PPP

YY

WW

A

LC

Primary sensed current

PPP

L...L

YY

Primary sensed current

YYWW

Date code: Calendar year (last two digits)

Date code: Calendar week

Lot code

Date code: Calendar year (last two digits)

Date code: Calendar week

Date code: Shift code

WW

The products described herein are manufactured under one or more

of the following U.S. patents: 5,045,920; 5,264,783; 5,442,283;

or manufacturability of its products. Before placing an order,

the user is cautioned to verify that the information being relied

5,389,889; 5,581,179; 5,517,112; 5,619,137; 5,621,319; 5,650,719; upon is current. The information included herein is believed to

5,686,894; 5,694,038; 5,729,130; 5,917,320; and other patents

pending.

be accurate and reliable. However, Allegro MicroSystems, Inc.

assumes no responsibility for its use; nor for any infringement of

patents or other rights of third parties which may result from its

use.

Allegro MicroSystems, Inc. reserves the right to make, from time

to time, such departures from the detail specifications as may be

required to permit improvements in the performance, reliability,

For the latest version of this document, go to our website at:

www.allegromicro.com

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

12

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

型号:	ACS71240KEXBLT-010B3
是否Rohs认证：	符合
生命周期：	Active
IHS 制造商：	ALLEGRO MICROSYSTEMS LLC
Reach Compliance Code：	compliant
风险等级：	5.58
Samacsys Confidence：	4
Samacsys Status：	Released
Samacsys PartID：	2219492
Samacsys Pin Count：	10
Samacsys Part Category：	Integrated Circuit
Samacsys Package Category：	Other
Samacsys Footprint Name：	EX-Package
Samacsys Released Date：	2019-08-11 09:15:06
Is Samacsys：	N
模拟集成电路 - 其他类型：	ANALOG CIRCUIT
湿度敏感等级：	2
峰值回流温度（摄氏度）：	NOT SPECIFIED
处于峰值回流温度下的最长时间：	NOT SPECIFIED
Base Number Matches：	1

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