ADE7753ARSZ Analog Devices Inc, ADE7753ARSZ Datasheet - Page 29

• 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

The ADE7753 achieves the integration of the active power
signal by continuously accumulating the active power signal in
an internal nonreadable 49-bit energy register. The active
energy register (AENERGY[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 14 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 1.1µs (4/CLKIN). As well as
calculating the energy, this integration removes any sinusoidal
components that might be in the active power signal. Figure 65
shows this discrete time integration or accumulation. The active
power signal in the waveform register is continuously added to
the internal active energy register. This addition is a signed
addition; therefore negative energy is subtracted from the active
energy contents. The exception to this is when POAM is
selected in the MODE[15:0] register. In this case, only positive
energy contributes to the active energy accumulation—see the
Positive-Only Accumulation Mode section.
The output of the multiplier is divided by WDIV. If the value in
the WDIV register is equal to 0, then the internal active energy
register is divided by 1. WDIV is an 8-bit unsigned register.
After dividing by WDIV, the active energy is accumulated in a
49-bit internal energy accumulation register. The upper 24 bits
of this register are accessible through a read to the active energy
register (AENERGY[23:0]). A read to the RAENERGY register
returns the content of the AENERGY register and the upper 24
bits of the internal register are cleared. As shown in Figure 65, the
active power signal is accumulated in an internal 49-bit signed
register. The active power signal can be read from the waveform
register by setting MODE[14:13] = 0,0 and setting the WSMP
bit (Bit 3) in the interrupt enable register to 1. Like the Channel
E
=
∫
p t dt
( )
=
Lim
t
→
0
⎧
⎨
⎩
V
∑
n
I
∞
=
VOLTAGE SIGNAL– v(t)
1
CURRENT SIGNAL – i(t)
p nT
(
)
×
MULTIPLIER
HPF
1
T
⎫
⎬
⎭
0x19999A
0x000000
Figure 65. Active Power Signal Processing
INSTANTANEOUS
POWER SIGNAL – p(t)
24
LPF2
Rev. A | Page 29 of 60
sgn
(14)
2
APOS [15:0]
6
+
2
5
+
2
-6
2
1 and Channel 2 waveform sampling modes, the waveform date
is available at sample rates of 27.9 kSPS, 14 kSPS, 7 kSPS, or
3.5 kSPS—see Figure 52.
Figure 66 shows this energy accumulation for full-scale signals
(sinusoidal) on the analog inputs. The three curves displayed
illustrate the minimum period of time it takes the energy register
to roll over when the active power gain register contents are
0x7FF, 0x000, and 0x800. The watt gain register is used to carry
out power calibration in the ADE7753. As shown, the fastest
integration time occurs when the watt gain register is set to
maximum full scale, i.e., 0x7FF.
Note that the energy register contents rolls over to full-scale
negative (0x800000) and continues to increase in value when
the power or energy flow is positive—see Figure 66. Conversely,
if the power is negative, the energy register underflows to full-
scale positive (0x7FFFFF) and continues to decrease in value.
By using the interrupt enable register, the ADE7753 can be
configured to issue an interrupt ( IRQ ) when the active energy
register is half-full (positive or negative) or when an overflow or
underflow occurs.
-7
2
0x7F,FFFF
0x3F,FFFF
-8
0x00,0000
0x40,0000
0x80,0000
WGAIN[11:0]
AENERGY [23:0]
Figure 66. Energy Register Rollover Time for Full-Scale Power
24
32
(Minimum and Maximum Power Gain)
4
0xCCCCD
0x19999
6.2
FOR WAVEFORM
ACCUMULATIOIN
FOR WAVEF0RM
SAMPLING
8
02875-0-064
12.5
02875-0-065
TIME (minutes)
WGAIN = 0x7FF
WGAIN = 0x000
WGAIN = 0x800
ADE7753