ADE7762ARWZ Analog Devices Inc, ADE7762ARWZ Datasheet - Page 15

• Manufacturer Part Number: ADE7762ARWZ
• Description: IC, POLYPHASE ENERGY METERING, SOIC-28
• Manufacturer: Analog Devices Inc

Specifications of ADE7762ARWZ

• Ic Function: Polyphase Energy Metering IC With Phase Drop Indication
• Supply Voltage Range: 4.75V To 5.25V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SOIC
• No. Of Pins: 28
• Input Impedance: 140 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.8V
• Current - Supply: 8.5mA
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-SOIC (0.300", 7.50mm Width)
• Meter Type: 3 Phase
• Brief Features: On-Chip Creep Protection, High Frequency Output
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-ADE7762EBZ - BOARD EVALUATION FOR ADE7762
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

TYPICAL CONNECTION DIAGRAMS
CURRENT CHANNEL CONNECTION
Figure 16 shows a typical connection diagram for the current
channel (IAN). A current transformer (CT) is the current trans-
ducer selected for this example. Notice that the common-mode
voltage for the current channel is AGND and is derived by
center-tapping the burden resistor to AGND. This provides the
complementary analog input signals for IAP and IAN. The CT
turns ratio and Burden Resistor Rb are selected to give a peak
differential voltage of ±500 mV at maximum load.
In theory, it is better to center-tap Rb; however, this requires
very careful attention to the layout and matching of the resistors
to ensure that the channels have the same resistance. A single
resistor may be more practical and is a valid design choice.
IP
VOLTAGE CHANNEL CONNECTION
Figure 17 shows two typical connections for the voltage chan-
nel. The first option uses a potential transformer (PT) to pro-
vide complete isolation from the main voltage. In the second
option, the ADE7762 is biased around the neutral wire, and a
resistor divider is used to provide a voltage signal proportional
to the line voltage. Adjusting the ratio of Ra, Rb, and VR is a
convenient way of carrying out a gain calibration on the meter.
VR can be implemented using either a potentiometer or a
binary weighted series of resistors. Either configuration works,
however, the potentiometer is subject to noise over time. Two
fixed value resistors can be used in place of VR to minimize
the noise.
PHASE
PHASE
PHASE
NEUTRAL
NEUTRAL
NEUTRAL
Figure 17. Typical Connections for Voltage Channels
Figure 16. Typical Connection for Current Channels
Ra*
VR*
Rb*
PT
CT
*Ra >> Rf + VR; *Rb + VR = Rf
AGND
±500mV
Cf
Rb
±500mV
Rf
Rf
±500mV
Rf
Rf
Rf
Cf
Cf
Cf
Cf
Cf
IAP
IAN
VAP
VAP
VN
VN
Rev. 0 | Page 15 of 28
METER CONNECTIONS
In 3-phase service, two main power distribution services exist:
3-phase, 4-wire or 3-phase, 3-wire. The additional wire in the
3-phase, 4-wire arrangement is the neutral wire. The voltage
lines have a phase difference of ±120° (±2π/3 radians) between
each other (see Equation 7).
where V
different phases.
The current inputs are represented by
where:
I
phase.
φ
voltage channel of each phase.
The instantaneous powers can then be calculated as follows:
Then,
As shown in Equation 9, the active power calculation per phase
is made when current and voltage inputs of one phase are
connected to the same channel (A, B, or C). Then the
summation of each individual active power calculation gives the
total active power information, P ( t ) = P
A
A
, I
, φ
B
, and I
P
P
P
V
V
V
B
V
I
I
I
P
P
P
, and φ
A
B
C
C
A
B
C
A
B
A
B
B
C
(t) = V
(t) = V
(t) = V
( )
( )
( )
( )
( )
( )
( )
( )
A
( )
t
t
t
t
t
×
t
t
t
t
, V
I
=
=
C
=
=
=
=
=
=
=
B
B
represent the rms value of the current of each
, and V
C
V
V
×
B
A
C
2
represent the phase difference of the current and
2
2
2
2
(t) × I
C
(t) × I
(t) × I
A
2
cos
×
×
×
I
I
I
×
×
A
B
C
V
V
I
V
I
( )
φ
C
×
×
×
B
A
A
C
C
B
A
C
B
cos
cos
cos
(t)
×
×
×
represent the voltage rms values of the
(t)
(t)
×
×
cos
cos
cos
cos
cos
−
⎛
⎜
⎝
⎛
⎜
⎝
(
ω
V
ω
ω
( )
( )
⎛
⎜
⎝
φ
( )
l
φ
⎛
⎜
⎝
l
B
ω
t
l
ω
t
t
C
ω
A
l
+
×
l
t
+
+
t
l
t
φ
I
+
−
2
−
4
+
B
3
3
A
π
π
V
2
V
×
3
4
)
π
3
+
C
+
A
π
cos
⎞
⎟
⎠
×
φ
φ
⎞
⎟
⎠
×
A
B
C
I
I
( t ) + P
⎛
⎜
⎝
C
⎞
⎟
⎠
⎞
⎟
⎠
A
2
×
ω
×
l
cos
cos
t
+
B
( t ) + P
⎛
⎜
⎝
(
4
2
2
ADE7762
3
π
ω
ω
+
l
l
t
t
C
φ
+
+
( t ).
B
φ
8
3
⎞
⎟
⎠
π
A
)
+
(7)
(8)
(9)
φ
C
⎞
⎟
⎠