ADE7763ARS Analog Devices Inc, ADE7763ARS Datasheet - Page 40

• 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

ADE7763
Phase Calibration
The PHCAL register is provided to remove small phase errors.
The ADE7763 co
time delay or advance on the voltage channel input. Phase leads
up to 1.84° and phase lags up to 0.72° at 50 Hz can be corrected.
The error is determined by measuring the active energy at I
two power factors, PF = 1 and PF = 0.5 inductive.
Some CTs may introduce large phase errors that are beyond the
range of the phase calibration register. In this case, coarse phase
compensation has to be done externally with an analog filter.
The phase error can be obtained from either CF or LAENERGY
measurements:
If watt gain and offset calibration have been performed, there
should be 0% error in CF at unity power factor, and then
The phase error is
The relationship between phase error and the PHCAL phase
correction register is
The expression for PHCAL can be simplified using the
assumption that at small x
The delay introduce
The delay associated with the PHCAL register i
PHCAL − 0x0D is po iv
quantity is negati . T re no time delay i
The phase correction is in the opposite dire
phase error.
Error =
Error = %ERROR
Phase Error (°) = −Arcsin
PHCAL = INT
Arcsin(x) ≈ x
Delay = (PHC
Phase Correction (°) = − (PHCAL − 0x0D
LAENERGY
ve he is
mpensates for phase error by inserting a small
AL − 0x0D) × 8/
⎛
⎜
⎝
d in the voltage channel by PHCAL is
Phase
sit e, b
CF(IB,PF = 0.5)
LAENERGY
IB
,
Error
PF
ut represen
=
⎛
⎜
⎜
⎝
0
/100
5 .
Error
( )
−
°
3
CLKIN
×
LAENERGY
IB
(
PERIOD
⎞
⎟
⎟
⎠
expected
ts a time advance if this
360
f PHCAL = 0x0D.
ction of the
°
)
2
)
⎞
⎟
⎠
s a time delay if
×
IB
+
(
PER
expected
0x0D
360
IOD
)
°
2
B
and
(52)
(53)
(54)
(55)
(56)
(57)
Rev. A | Page 40 of 56
Calibrating Phase Using a Reference Meter Example
A power factor of 0.5 inductive can be assumed if the
output rate of the reference meter is half of its PF
Then, the percent error between CF and the pulse output o
the reference mete
calculations.
For this example:
CF %ERROR at PF = 0.5 Inductive: %ERROR
PERIOD Register Reading:
Then PHCAL is 11 using Equations 57 through 59:
PHCAL can be expressed as follows:
Note that PHCAL is a signed, twos complement register.
Setting the PHCAL register to 11 provides a phase correction
of 0.08° t
Error = 0.215%/100 = 0.00215
Phase Error (°) = −Arcsin
PHCAL = INT
PHCAL =
INT
Phase Correction (°) = −
Phase Corr
o correct the phase lead:
⎛
⎜
⎜
⎝
Figure 75. Calibrating Phase Using a Reference Meter
−
Arcsin
CALCULATE PHCAL. SEE EQUATION 55.
WRITE PHCAL VALUE TO THE PHCAL
ection (°) = −
SET I
MEASURE THE % ERROR BETWEEN
r ca
REFERENCE METER OUTPUT
⎛
⎜ ⎜
⎝
⎛
⎜
⎝
TEST
THE CF OUTPUT AND THE
−
%
REGISTER: ADDR. 0x10
n be used to perform the preceding
. 0
ERROR
= I
07
b
, V
°
TEST
×
3
(
(
11
PHCAL
8959
⎛
⎜ ⎜
⎝
360
×
. 0
= V
−
100
PERIOD = 8959
00215
°
NOM
0x0D
⎞
⎟
⎠
3
⎞
⎟ ⎟
⎠
+0x0D = −2 + 13 = 11
, PF = 0.5
×
−
)
⎞
⎟ ⎟
⎠
PERIOD
0x0D
×
=
8960
2
360
−
CF(IB,PF = 0.5)
π
. 0
)
×
°
07
=
PERIOD
= 1 ate.
⎞
⎟
⎟
⎠
°
+
. 0
360
08
0x0D
r
pulse
= 0.215%
°
°
f
(58)