ADE7763ARSZRL Analog Devices Inc, ADE7763ARSZRL Datasheet - Page 36

• Manufacturer Part Number: ADE7763ARSZRL
• Description: IC ENERGY METERING 1PHASE 20SSOP
• Manufacturer: Analog Devices Inc

Specifications of ADE7763ARSZRL

• 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 Active And Apparent Energy 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-ADE7763ZEB - BOARD EVALUATION FOR ADE7763
• Lead Free Status / Rohs Status: Compliant
• Other names: ADE7763ARSZRL; ADE7763ARSZRLTR

ADE7763
With the CFNUM register set to 0, CFDEN is calculated to be
489 for the example meter:
This value for CFDEN should be loaded into each meter before
calibration. The WGAIN register can then be used to finely
calibrate the CF output. The following sections explain how to
calibrate a meter based on ADE7763 when using a reference
meter or an accurate source.
Calibrating Watt Gain Using a Reference Meter Example
The CFDEN and CFNUM values for the design should be
written to their respective registers before beginning the
calibration steps shown in Figure 71. When using a reference
meter, the percent error in CF is measured by comparing the CF
output of the ADE7763 meter with the pulse output of the
reference meter, using the same test conditions for both meters.
Equation 41 defines the percent error with respect to the pulse
outputs of both meters (using the base current, I
CFDEN =
CFDEN =
%ERROR
Figure 71. Calibrating Watt Gain Using a Reference Meter
WRITE CFDEN VALUE TO CFDEN REGISTER
CF(IB)
CALCULATE CFDEN VALUE FOR DESIGN
CALCULATE WGAIN. SEE EQUATION 42.
INT
INT
WRITE WGAIN VALUE TO THE WGAIN
MEASURE THE % ERROR BETWEEN
SET I
=
REFERENCE METER OUTPUT
THE CF OUTPUT AND THE
⎛
⎜
⎜
⎝
⎛
⎜
⎝
TEST
REGISTER: ADDR. 0x12
. 1
CF
CF
CF
ADDR. 0x15 = CFDEN
958
9556
IB
IB
= I
IB
CF
(
(
b
nominal
expected
−
, V
ref
⎞
⎟
⎠
CF
TEST
(
−
IB
ref
)
1
)
)
= V
⎞
⎟
⎟
⎠
=
(
IB
−
NOM
(
)
490
1
×
, PF = 1
100
−
) 1
=
489
b
):
(40)
(41)
Rev. B | Page 36 of 56
For this example:
Meter Constant:
CF Numerator:
CF Denominator:
%ERROR Measured at Base Current:
One LSB change in WGAIN changes the active energy registers
and CF by 0.0244%. WGAIN is a signed, twos complement
register and can correct up to a 50% error. Assuming a −3.07%
error, WGAIN is 126:
When CF is calibrated, the AENERGY register has the same
Wh/LSB constant from meter to meter if the meter constant,
WDIV, and the CFNUM/CFDEN ratio remain the same. The
Wh/LSB ratio for this meter is 6.378 × 10
with WDIV at the default value.
Calibrating Watt Gain Using an Accurate Source Example
The CFDEN value calculated using Equation 40 should be
written to the CFDEN register before beginning calibration and
zero should be written to the CFNUM register. Enable the line
accumulation mode and the line accumulation interrupt. Then,
write the number of half line cycles for the energy accumulation
to the LINECYC register to set the accumulation time. Reset the
interrupt status register and wait for the line cycle accumulation
interrupt. The first line cycle accumulation results might not
use the accumulation time set by the LINECYC register and,
therefore, should be discarded. After resetting the interrupt
status register, the following line cycle readings will be valid.
When LINECYC half line cycles have elapsed, the IRQ pin goes
active low and the nominal LAENERGY with the test current
applied can be read. This LAENERGY value is compared to the
expected LAENERGY value to determine the WGAIN value. If
apparent energy gain calibration is performed at the same time,
LVAENERGY can be read directly after LAENERGY. Both
registers should be read before the next interrupt is issued on
the IRQ pin.
using an accurate source.
WGAIN = INT
WGAIN = INT
Wh
Wh
LSB
LSB
Figure 72
=
=
. 3
MeterConst
(
200
(
CFNUM
CFDEN
(
490
⎛
⎜ ⎜
⎝
⎛
⎜
⎝
−
imp/Wh
−
1
details steps to calibrate the watt gain
%
. 0
+
−
ERROR
. 3
0244
) 1
. 0
+
07
+
ant
0244
MeterConstant(imp/Wh) = 3.2
CFNUM = 0
CFDEN = 489
%ERROR
) 1
) 1
%
%
(imp/Wh)
=
×
CF
⎞
⎟
⎠
%
WDIV
490
=
(IB
126
)
1
×
CF(IB)
⎞
⎟ ⎟
⎠
3
2 .
−4
= −3.07%
using Equation 35
=
. 6
378
×
10
−
4
(42)