ADE7758ARWZ Analog Devices Inc, ADE7758ARWZ Datasheet - Page 50

• 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
Step 5: Set the LENERGY bit, MASK[12] (0x18), to Logic 1
to enable the interrupt signaling the end of the line cycle
accumulation.
Step 6: Set the test system for I
(calibrate watt and VA simultaneously and first).
Step 7: Read the FREQ (0x10) register if the line frequency is
unknown.
Step 8: Reset the interrupt status register by reading
RSTATUS (0x1A).
Step 9: Read all six xWATTHR (0x01 to 0x03) and xVAHR
(0x07 to 0x09) energy registers after the LENERGY interrupt
and store the values.
Step 9a: Calculate the values to be written to xWG registers
according to the following equations:
where AccumTime is
where:
MC is the meter constant.
θ is the angle between the current and voltage.
Line Frequency is known or calculated from the FREQ[11:0]
register. With the FREQ[11:0] register configured for line period
measurements, the line frequency is calculated with Equation 62.
No. of Phases Selected is the number of ZXSEL bits set to Logic 1
in LCYCMODE (0x17).
Then, xWG is calculated as
WATTHR
Line
xWG
4
2
APCFNUM
APCFDEN
×
×
Line
MC
Frequency
=
⎛
⎜
⎜
⎝
×
Frequency
WATTHR
WATTHR
I
EXPECTED
TEST
×
LINECYC
WDIV
×
=
1000
V
1
FREQ
NOM
=
×
MEASURED
EXPECTED
No.
×
×
3600
[
[11
cos
15
TEST
of
:
0
( )
:
Phases
, V
θ
0]
−
]
1
1 × ⎟ ⎟
×
×
NOM
⎞
⎠
9.6
AccumTime
2
, and unity power factor
Selected
×
12
10
6 -
×
(60)
(61)
(62)
(63)
Rev. D | Page 50 of 72
Step 9b: Calculate the values to be written to the xVAG registers
according to the following equation:
Step 10: Write to xWG and xVAG.
Step 11: Set the test system for I
factor inductive to calibrate VAR gain.
Step 12: Repeat Step 7.
Step 13: Read the xVARHR (0x04 to 0x06) after the LENERGY
interrupt and store the values.
Step 14: Calculate the values to be written to the xVARG
registers (to adjust VARCF to the expected value).
Step 15: Write to xVARG.
Step 16: Calculate the Wh/LSB, VARh/LSB, and VAh/LSB
constants.
Example: Watt Gain Calibration Using Line Accumulation
This example shows only Phase A watt calibration. The steps
outlined in the Gain Calibration Using Line Accumulation
section show how to calibrate watt, VA, and VAR. All three
phases can be calibrated simultaneously because there are nine
energy registers.
For this example, I
Frequency = 50 Hz, LINECYC (0x1C) is set to 0x800, and MC =
3200 imp/kWhr.
VAHR
VARHR
VARCFNUM
4
4
VARCFDEN
×
×
MC
MC
xVAG
xVARG
VAh
VARh
LSB
Wh
LSB
LSB
EXPECTED
EXPECTED
×
×
=
I
I
=
TEST
TEST
=
=
I
1000
I
TEST
=
⎛
⎜
⎜
⎝
TEST
I
×
VAHR
TEST
VAHR
⎛
⎜
⎜
⎝
=
×
×
1000
VARDIV
VARHR
=
VARHR
V
V
×
×
×
TEST
3600
NOM
NOM
V
×
3600
V
3600
1
NOM
V
NOM
MEASURED
×
EXPECTED
= 10 A, V
NOM
×
×
3600
3600
×
MEASURED
AccumTime
sin
EXPECTED
×
×
×
xVAHR
cos
×
xWATTHR
AccumTime
( )
θ
×
sin
( )
xVARHR
θ
−
×
TEST
( )
NOM
θ
1 × ⎟ ⎟
AccumTime
×
⎞
⎠
−
, V
×
AccumTime
1 × ⎟ ⎟
= 220 V, Power Factor = 1,
2
⎞
⎠
AccumTime
NOM
×
12
VARCFNUM
VARCFDEN
2
12
, and zero power
×
×
VADIV
(65)
1
(64)
(66)
(67)
(68)