ADE7758ARW Analog Devices Inc, ADE7758ARW Datasheet - Page 48

• Manufacturer Part Number: ADE7758ARW
• Description: IC ENERGY METERING 24-SOIC
• Manufacturer: Analog Devices Inc

Specifications of ADE7758ARW

• Rohs Status: RoHS non-compliant
• 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
• Lead Free Status / RoHS Status: Not Compliant

ADE7758
where Q is defined in Equation 58 and Equation 59.
For xWATTOS,
For xVAROS,
where the FREQ (0x10) register is configured for line period
measurements.
Step 7: Repeat Step 3 to Step 6 for xVAROS calibration.
Example: Offset Calibration of Phase A Using Pulse Output
For this example, I
500 V, I
Factor = 1, Frequency = 50 Hz, and CLKIN = 10 MHz.
With I
meter shows 0.009789 Hz on the APCF pulse output. When the
power factor is changed to 0.5 inductive, the VARCF output is
0.009769 Hz.
This is equivalent to 0.1198% for the watt measurement and
−0.0860% for the VAR measurement. Using Equation 56
through Equation 59, the values 0xFFD and 0x3 should be
written to AWATTOS (0x39) and AVAROS (0x3C), respectively.
–
Q
Q
–
xVAROS
AWATTOS
AVAROS
VARCFNUM
VARCFDEN
MIN
⎛
⎜
⎝
⎛
⎜
⎝
=
=
FULLSCALE
%VARCF
0.1198%
, V
CLKIN
CLKIN
100
NOM
100
4
4
%
=
=
= 130 A, MC = 3200 impulses/kWh, Power
, and unity power factor, the example ADE7758
%
–
×
=
ERROR
×
×
⎛
⎜
⎝
MIN
0.009778
2
2
–
1
1
25
24
0.0860%
= 50 mA, V
100
×
×
×
VARCF
1
4
⎛
⎜
⎝
%
FREQ
⎞
⎟
⎠
×
×
202
0.01863
0.009778
4
EXPECTED
[11
NOM
2
4
:
0]
= 220 V, V
⎞
⎟
⎠
×
⎞
⎟
⎠
×
⎞
⎟
⎠
×
277
×
1
4
1
2
Q
0.01444
4
=
×
2
FULLSCALE
–2.8
4
=
×
–
277
=
3
1
=
=
(57)
(58)
(59)
0xFFD
Rev. D | Page 48 of 72
2.6
=
3
For AWATTOS,
For AVAROS,
Calibration Using Line Accumulation
Line cycle accumulation mode configures the nine energy
registers such that the amount of energy accumulated over an
integer number of half line cycles appears in the registers after
the LENERGY interrupt. The benefit of using this mode is that
the sinusoidal component of the active energy is eliminated.
Figure 80 shows a flowchart of how to calibrate the ADE7758
using the line accumulation mode. Calibration of all phases and
energies can be done simultaneously using this mode to save
time during calibration.
Q
Q
=
=
10
10
4
4
E
E
Figure 80. Calibration Using Line Accumulation
6
6
×
×
2
2
1
1
25
24
×
×
OFFSET @ I
1
4
CAL VRMS OFFSET
CAL VAR GAIN ALL
CALIBRATE PHASE
CAL WATT AND VA
2083
CAL IRMS OFFSET
GAIN ALL PHASES
PHASES @ PF = 0,
202
CALIBRATE ALL
CALIBRATE ALL
OFFSETS @ I
PHASES WATT
=
4
PHASES VAR
ALL PHASES
AND PF = 0,
INDUCTIVE
@ PF = 0.5,
INDUCTIVE
INDUCTIVE
. 0
@ PF = 1
START
PF = 1
01863
END
×
1
4
MIN
=
MIN
AND
0.01444