Fully Integrated, Hall Effect-Based Linear Current Sensor with

2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor

ACS712

9

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

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

www.allegromicro.com

Rise Time versus External Filter Capacitance

0

200

400

600

800

1000

1200

0

100

200

300

400

500

Power on Time versus External Filter Capacitance

0

20

40

60

80

100

120

140

160

180

200

0

10

20

30

40

50

Expanded in chart at right

Rise Time versus External Filter Capacitance

0

150

200

250

300

350

400

0

50

75

100

125

150

Noise versus External Filter Capacitance

1

100

10

1000

0.01

0.1

1

10

100

1000

}

Definitions of Dynamic Response Characteristics

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

90

0

I (%)

Propagation Time, t

PROP

t

Primary Current

Transducer Output

90

0

I (%)

t

Primary Current

Transducer Output

90

10

0

I (%)

t

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) =

current losses observed in the conductive IC ground plane.

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.

Excitation Signal

Output (mV)

15 A

Step Response

0

6.647

1

7.74

4.7

17.38

10

32.09087

22

68.15

47

88.18

100

291.26

220

623.02

470

1120