ADE7758 Analog Devices, ADE7758 Datasheet - Page 46

• Manufacturer Part Number: ADE7758
• Description: Poly Phase Multifunction Energy Metering IC with Per Phase Information
• Manufacturer: Analog Devices

ADE7758
Step 1: Repeat Step 1 and Step 3 from the gain calibration to
configure the ADE7758 pulse output.
Step 2: Set the xWATTOS and xVAROS registers to Logic 0.
Step 3: Set the test system for I
factor. For Step 6, set the test system for I
zero-power factor.
Step 4: Measure the percent error in the pulse output, APCF or
VARCF, from the reference meter using Equation 31.
Step 5: Calculate xWATTOS using Equation 38 (for xVAROS
use Equation 39).
–
xWATTOS
(
%
APCF
ERROR
=
×
APCF
END
EXPECTED
TEST
YES
= I
)
MIN
×
STEP 6.
REPEAT STEP
3 TO STEP 5
FOR XVAROS
2
Q
, V
4
TEST
CALIBRATED?
ALL PHASES
VAR OFFSET
×
NOM
APCFNUM
= I
APCFDEN
, and unity power
MIN
Figure 79. Offset Calibration Using Pulse Output
, V
NOM
ERROR FOR VARCF
STEP 3
STEP 4
STEP 5
MEASURE PERIOD
(38)
CALCULATE AND
FOR PHASE A, B,
, and
SET UP SYSTEM
PULSE OUTPUT
FOR I
SET UP VARCF
USING PERIOD
NO
START
MEASURE %
REGISTER
WRITE TO
XVAROS
Rev. A | Page 46 of 68
PF = 0
OR C
MIN
, V
NOM
YES
,
where Q is defined in Equation 40 and Equation 41.
For xWATTOS
For xVAROS
where PERIOD is measured from the FREQ (0x10) register.
Step 6: Repeat Step 3 to Step 5 for xVAROS calibration.
STEP 1
STEP 2
XWATTOS, XVAROS
CALIBRATED?
SET OFFSET
OFFSET AND
ENABLE CF
REGISTERS
ALL PHASES
TO LOGIC 0
VA OFFSET
OUTPUT
–
Q
Q
xVAROS
WATT
(
%
=
=
VARCF
CLKIN
CLKIN
4
4
=
ERROR
×
×
STEP 3
STEP 4
STEP 5
2
FOR PHASE A, B,
CALCULATE AND
2
SET UP SYSTEM
PULSE OUTPUT
FOR I
1
1
NO
24
25
SET UP APCF
MEASURE %
ERROR FOR
×
WRITE TO
XWATTOS
VARCF
×
×
PF = 1
APCF
OR C
MIN
1
⎛
⎜
⎝
4
, V
PERIOD
NOM
202
EXPECTED
4
,
⎞
⎟
⎠
×
)
×
1
4
2
Q
4
×
VARCFNUM
VARCFDEN
(39)
(40)
(41)