ADE7753ARSZ Analog Devices Inc, ADE7753ARSZ Datasheet - Page 35

• 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

Apparent Power Offset Calibration
Each rms measurement includes an offset compensation
register to calibrate and eliminate the dc component in the rms
value—see Channel 1 RMS Calculation and Channel 2 RMS
Calculation sections. The Channel 1 and Channel 2 rms values
are then multiplied together in the apparent power signal
processing. Since no additional offsets are created in the
multiplication of the rms values, there is no specific offset
compensation in the apparent power signal processing. The
offset compensation of the apparent power measurement is
done by calibrating each individual rms measurement.
APPARENT ENERGY CALCULATION
The apparent energy is given as the integral of the apparent
power.
The ADE7753 achieves the integration of the apparent power
signal by continuously accumulating the apparent power signal
in an internal 48-bit register. The apparent energy register
(VAENERGY[23:0]) represents the upper 24 bits of this internal
register. This discrete time accumulation or summation is
equivalent to integration in continuous time. Equation 31
expresses the relationship
where:
n is the discrete time sample number.
T is the sample period.
The discrete time sample period (T) for the accumulation
register in the ADE7753 is 1.1 µs (4/CLKIN).
Figure 75 shows this discrete time integration or accumulation.
The apparent power signal is continuously added to the internal
register. This addition is a signed addition even if the apparent
energy remains theoretically always positive.
Apparent
Apparent
Figure 74. Apparent Power Calculation Output Range
0x103880
0xAD055
0x5682B
0x00000
APPARENT POWER 100% FS
Energy
Energy
CHANNEL INPUTS: 0.5V/GAIN
VOLTAGE AND CURRENT
0x000
CALIBRATION RANGE
APPARENT POWER
=
=
{VAGAIN[11:0]}
T
Lim
APPARENT POWER 150% FS
∫
→
Apparent
0
0x7FF
⎧
⎪
⎨
⎪ ⎩
∑
n
∞
=
0
APPARENT POWER 50% FS
Apparent
0x800
Power
Power
(
t
)
02875-0-073
dt
(
nT
)
×
T
⎫
⎪
⎬
⎪ ⎭
Rev. A | Page 35 of 60
(30)
(31)
The 49 bits of the internal register are divided by VADIV. If the
value in the VADIV register is 0, then the internal active energy
register is divided by 1. VADIV is an 8-bit unsigned register. The
upper 24 bits are then written in the 24-bit apparent energy
register (VAENERGY[23:0]). RVAENERGY register (24 bits
long) is provided to read the apparent energy. This register is
reset to 0 after a read operation.
Figure 76 shows this apparent energy accumulation for full-scale
signals (sinusoidal) on the analog inputs. The three curves
displayed illustrate the minimum time it takes the energy register
to roll over when the VAGAIN registers content is equal to 0x7FF,
0x000, and 0x800. The VAGAIN register is used to carry out an
apparent power calibration in the ADE7753. As shown, the fastest
integration time occurs when the VAGAIN register is set to
maximum full scale, i.e., 0x7FF.
APPARENT POWER
0xFF,FFFF
0x80,0000
0x40,0000
0x20,0000
0x00,0000
VAENERGY[23:0]
Figure 76. Energy Register Rollover Time for Full-Scale Power
T
Figure 75. ADE7753 Apparent Energy Calculation
(Maximum and Minimum Power Gain)
ACTIVE POWER
6.26
SIGNAL = P
TIME (nT)
+
12.52
+
48
48
23
18.78
VADIV
VAENERGY [23:0]
25.04
APPARENT POWER ARE
ACCUMULATED (INTEGRATED) IN
THE APPARENT ENERGY REGISTER
%
0
VAGAIN = 0x7FF
VAGAIN = 0x000
VAGAIN = 0x800
ADE7753
TIME (minutes)
02875-0-075
02875-0-074
0
0