ADE7753ARSZ Analog Devices Inc, ADE7753ARSZ Datasheet - Page 27

• Manufacturer Part Number: ADE7753ARSZ
• Description: IC ENERGY METERING 1PHASE 20SSOP
• Manufacturer: Analog Devices Inc

Specifications of ADE7753ARSZ

• 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
• Ic Function: Single-Phase Multifunction Metering IC
• Supply Voltage Range: 4.75V To 5.25V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SSOP
• No. Of Pins: 20
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-ADE7753ZEB - BOARD EVALUATION AD7753
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

ACTIVE POWER CALCULATION
Power is defined as the rate of energy flow from source to load.
It is defined as the product of the voltage and current wave-
forms. The resulting waveform is called the instantaneous
power signal and is equal to the rate of energy flow at every
instant of time. The unit of power is the watt or joules/sec.
Equation 9 gives an expression for the instantaneous power
signal in an ac system.
where:
V is the rms voltage.
I is the rms current.
The average power over an integral number of line cycles (n) is
given by the expression in Equation 10.
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 component of the
instantaneous power signal p(t) in Equation 8, i.e., VI. This is
the relationship used to calculate active power in the ADE7753.
Figure 60. Combined Gain Response of the HPF and Phase Compensation
v(t) =
i(t) =
P =
p
p
) (
(
–0.1
–0.2
–0.3
–0.4
t
t
0.4
0.3
0.2
0.1
0.0
)
nT
=
=
1
54
VI
v
2
∫
2
(
×
t
0
−
×
nT
)
I
VI
V
×
p
sin(
56
t i
) (
sin(
cos(
(
t
dt
)
ω
ω
t
2
=
t
)
ω
)
VI
t
58
)
FREQUENCY (Hz)
60
62
64
02875-0-059
66
Rev. A | Page 27 of 60
(10)
(7)
(8)
(9)
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 61.
Since LPF2 does not have an ideal “brick wall” frequency
response—see Figure 62, the active power signal has some
ripple due to the instantaneous power signal. This ripple is
sinusoidal and has a frequency equal to twice the line frequency.
Because the ripple is sinusoidal in nature, it is removed when
the active power signal is integrated to calculate energy—see the
Energy Calculation section.
0xCCCCD
0x19999A
0x00000
VI
–12
–16
–20
–24
–4
–8
0
1
INSTANTANEOUS
POWER SIGNAL
CURRENT
i(t) = 2
Figure 62. Frequency Response of LPF2
Figure 61. Active Power Calculation
VOLTAGE
v(t) = 2
×
i
×
3
sin(ωt)
×
v
×
FREQUENCY (Hz)
sin(ωt)
p(t) = v
10
×
i-v
×
i
×
cos(2ωt)
ACTIVE REAL POWER
SIGNAL = v
30
ADE7753
02875-0-061
×
i
100
02875-0-060