Electrical characteristics, Absolute maximum ratings, Calibration characteristics – Rainbow Electronics AT73C502 User Manual
Page 24: Measurement accuracy, Input conditions

AT73C500
24
Electrical Characteristics
Measurement Accuracy
The accuracy measurements are based on the usage of
t h e A T 7 3 C 5 0 0 D S P w i t h t h e s i n g l e - e n d e d A D C ,
AT73C501. Using the differential-ended ADC, AT73C502,
improves some of the results.
Input Conditions
When specifying measurement accuracy, it is assumed
that 80A
RMS
phase current will produce 2V
PP
full scale input
voltage to current converters. The basic current, I
B
, is sup-
posed to be 5A
RMS
.
The nominal phase voltage, U
N
, is specified to be 230V
RMS
and 2V
PP
full scale input is produced by 270V
RMS
.
Overall Accuracy, Active and Reactive Power and
Energy Measurement
Overall accuracy including errors caused by A/D-conver-
sion of current and voltage signals, calibration and calcula-
tions.
The accuracy figures are measured in nominal conditions
unless otherwise indicated in the parameter field of the
table below.
Absolute Maximum Ratings
Parameter
Min
Typ
Max
Unit
Supply Voltage V
CC
,
V
DA
, V
DDA
4.75
5.25
V
Input Voltage, Digital
-0.3
V
DD
+0.3
V
Input Voltage, Analog
-0.3
V
DA
+0.3
V
Input Voltage, CI and
VI inputs
1.25
3.75
V
Ambient Operating
Temp.
-25
+70
C
Storage Temperature
-65
+150
C
Calibration Characteristics
Parameter
Min
Typ
Max
Units
Gain Calibration
Calibration Range
±
20
%
Calibration
Resolution
0.16
%
Phase Calibration
Calibration Range
±
5.625
degree
Calibration
Resolution
0.044
degree
Offset Calibration,
Active Power
Calibration Range
89.8
W
Calibration
Resolution
0.7015
W
Range,% of Full
Scale Phase Power
0.4157
%
Offset Calibration,
Reactive Power
Calibration Range
98.7
VAr
Calibration
Resolution
0.7712
VAr
Range,% of Full
Scale Phase Power
0.457
%
Parameter
Nominal Value
Nominal voltage, U
N
230V,
±
1%
Full-scale voltage, U
FS
270V
Full-scale current, I
FS
80A
Base current, I
B
5A
Frequency, f
50.0 Hz,
±
0.3%
Power factor, PF
1
Harmonic contents of voltage
less than 2%
Harmonic contents of current
less than 20%
Temperature, T
23
°
C,
±
2
°
C
AT73C500 master clock
3.2768 MHz