ADE7758ARWZ Analog Devices Inc, ADE7758ARWZ Datasheet - Page 20

• Manufacturer Part Number: ADE7758ARWZ
• Description: IC ENERGY METERING 3PHASE 24SOIC
• Manufacturer: Analog Devices Inc

Specifications of ADE7758ARWZ

• Input Impedance: 380 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.8V
• Current - Supply: 8mA
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (0.300", 7.50mm Width)
• Meter Type: 3 Phase
• Ic Function: Poly Phase Multifunction Energy Metering IC
• Supply Voltage Range: 4.75V To 5.25V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SOIC
• No. Of Pins: 24
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADE7758
di/dt CURRENT SENSOR AND DIGITAL INTEGRATOR
The di/dt sensor detects changes in the magnetic field caused by
the ac current. Figure 42 shows the principle of a di/dt current
sensor.
The flux density of a magnetic field induced by a current is
directly proportional to the magnitude of the current. The
changes in the magnetic flux density passing through a conductor
loop generate an electromotive force (EMF) between the two
ends of the loop. The EMF is a voltage signal that is propor-
tional to the di/dt of the current. The voltage output from the
di/dt current sensor is determined by the mutual inductance
between the current carrying conductor and the di/dt sensor.
The current signal needs to be recovered from the di/dt signal
before it can be used. An integrator is therefore necessary to
restore the signal to its original form. The ADE7758 has a built-
in digital integrator to recover the current signal from the di/dt
sensor. The digital integrator on Channel 1 is disabled by default
when the ADE7758 is powered up. Setting the MSB of the
GAIN[7:0] register turns on the integrator. Figure 43 to Figure 46
show the magnitude and phase response of the digital
integrator.
–10
–20
–30
–40
–50
20
10
0
10
Figure 42. Principle of a di/dt Current Sensor
Digital Integrator and Phase Compensator
Figure 43. Combined Gain Response of the
100
FREQUENCY (Hz)
MAGNETIC FIELD CREATED BY CURRENT
(DIRECTLY PROPORTIONAL TO CURRENT)
+ EMF (ELECTROMOTIVE FORCE)
– INDUCED BY CHANGES IN
MAGNETIC FLUX DENSITY (di/dt)
1k
10k
Rev. D | Page 20 of 72
89.80
89.85
89.90
89.95
90.00
90.05
90.10
80
81
82
83
84
85
86
87
88
89
90
91
–1
Digital Integrator and Phase Compensator (40 Hz to 70 Hz)
Digital Integrator and Phase Compensator (40 Hz to 70 Hz)
5
4
3
2
1
0
10
40
40
Figure 44. Combined Phase Response of the
Figure 46. Combined Phase Response of the
Digital Integrator and Phase Compensator
Figure 45. Combined Gain Response of the
45
45
100
50
50
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
55
55
1k
60
60
65
65
10k
70
70