ADE7763ARS Analog Devices Inc, ADE7763ARS Datasheet - Page 27

• Manufacturer Part Number: ADE7763ARS
• Description: IC ENERGY METER 1PHASE 20SSOP
• Manufacturer: Analog Devices Inc

Specifications of ADE7763ARS

• 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-ADE7763ZEB - BOARD EVALUATION FOR ADE7763
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

The ADE7763 achieves the integration of the active power
signal by continuously accumulating the active power signal in
an internal unreadable 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 this relationship.
where:
n is the discrete time sample number.
T is the sample period.
The discrete time sample period ( T ) for the accumulation
register is 1.1 μs (4/CLKIN). In addition to calculating the
energy, this integration removes any sinusoidal components
that might be in the active power signal.
Figure 57 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 which 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 57,
the active power signal is accumulated in an internal 49-bit,
signed register. The active power signal can be read from the
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
⎫
⎬
⎭
0x19 999A
0x00 0000
Figure 57. Active Power Signal Processing
INSTANTANEOUS
POWER SIGNAL – p(t)
24
LPF2
(14)
Rev. B | Page 27 of 56
sgn
2
APOS[15:0]
6
+
2
5
+
2
-6
2
waveform register by setting MODE[14:13] = 0, 0 and setting
the WSMP bit (Bit 3) in the interrupt enable register to 1. Like
Channel 1 and Channel 2 waveform sampling modes, the
waveform data is available at sample rates of 27.9 kSPS, 14 kSPS,
7 kSPS, or 3.5 kSPS—see Figure 44.
Figure 58 shows this energy accumulation for full-scale signals
(sinusoidal) on the analog inputs. The three curves illustrate the
minimum time for 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. 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 roll over to full-scale
negative (0x80 0000) and continue increasing in value when the
power or energy flow is positive—see Figure 58. Conversely, if
the power was negative, the energy register would underflow to
full-scale positive (0x7F FFFF) and continue decreasing in
value.
By using the interrupt enable register, the ADE7763 can be
configured to issue an interrupt ( IRQ ) when the active energy
register is more than 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 58. Energy Register Rollover Time for Full-Scale Power
24
32
(Minimum and Maximum Power Gain)
0xC CCCD
4
0x1 9999
6.2
FOR WAVEFORM
FOR WAVEF0RM
ACCUMULATION
SAMPLING
8
12.5
TIME (minutes)
WGAIN = 0x7FF
WGAIN = 0x000
WGAIN = 0x800
ADE7763