ADE7759ARSRL Analog Devices Inc, ADE7759ARSRL Datasheet - Page 20

• Manufacturer Part Number: ADE7759ARSRL
• Description: IC ENERGY METERING 1PHASE 20SSOP
• Manufacturer: Analog Devices Inc

Specifications of ADE7759ARSRL

• Rohs Status: RoHS non-compliant
• Input Impedance: 390 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.8V
• Current - Supply: 3mA
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-SSOP (0.200", 5.30mm Width)
• Meter Type: Single Phase
• For Use With: EVAL-ADE7759EBZ - BOARD EVALUATION FOR ADE7759

ADE7759
V1
V2
Figure 29. Combined Phase Response of the HPF and
Phase Compensation (100 Hz to 1 kHz)
Figure 30. Combined Phase Response of the HPF and
Phase Compensation (40 Hz to 70 Hz)
V1N
V2N
V1P
V2P
V1
–0.05
–0.10
–0.05
–0.10
0.30
0.25
0.20
0.15
0.10
0.05
0.00
PGA1
PGA2
0.30
0.25
0.20
0.15
0.10
0.05
0.00
V2
40
60Hz
100
Figure 28. Phase Calibration
ADC 2
0.1
ADC 1
45
200
300
1
50
7
FREQUENCY – Hz
400
FREQUENCY – Hz
1
–110 s TO +103 s
DELAY BLOCK
1
1.12 s/LSB
PHCAL [7:0]
1
500
55
1
HPF
1
600
1
0
60
20
700
0
0
800
CHANNEL 2 DELAY
REDUCED BY 4.48 s
(0.1 LEAD AT 60Hz)
FCH IN PHCAL [7:0]
V2
65
20
V1
60Hz
900
LPF2
1000
70
–20–
Figure 31. Combined Gain Response of the HPF and Phase
Compensation (Deviation of Gain in % from Gain at 60 Hz)
ACTIVE POWER CALCULATION
Electrical power is defined as the rate of energy flow from source to
load. It is given by the product of the voltage and current wave-
forms. The resulting waveform is called the instantaneous power
signal, and it is equal to the rate of energy flow at every instant
of time. The unit of power is the watt or joules/second. Equa-
tion 3 gives an expression for the instantaneous power signal in
an ac system.
where:
V = rms voltage
I = rms current
The average power over an integral number of line cycles (n) is
given by the expression in Equation 4.
where T is the line cycle period. P is referred to as the active or
real power. Note that the active power is equal to the dc compo-
nent of the instantaneous power signal p(t) in Equation 3, i.e.,
VI. This is the relationship used to calculate active power in the
ADE7759. The instantaneous power signal p(t) is generated by
multiplying the current and voltage signals. The dc component
of the instantaneous power signal is then extracted by LPF2 (low-
pass filter) to obtain the active power information. This process
is illustrated in Figure 32. Since LPF2 does not have an ideal
“brick wall” frequency response (see Figure 33), the active power
signal will have some ripple due to the instantaneous power
signal. This ripple is sinusoidal and has a frequency equal to twice
the line frequency. Since the ripple is sinusoidal in nature, it will
be removed when the active power signal is integrated to calcu-
late energy—see Energy Calculation section.
v t
i t
P
p t
p t
( )
( )
( )
( )
=
= 2
= 2
=
=
nT
–0.1
–0.2
–0.3
–0.4
1
0.4
0.3
0.2
0.1
0.0
VI VI
v t
( )
54
nT
0
∫
–
V
I
p t dt VI
×
sin(
(
( )
ω
i t
( )
cos(
t
)
ω
56
t
)
=
2ω
t
)
58
FREQUENCY – Hz
60
62
64
REV. A
66
(1)
(2)
(3)
(4)