AT73C501 View Datasheet(PDF) - Atmel Corporation
Part Name
Description
MFG CO.
'AT73C501' PDF : 28 Pages View PDF
AT73C500
It is recommended that 50 Hz meters are operated from
3.2768MHz crystal. In 60 Hz system, a 3.93216 MHz clock
is normally used. Because the clock frequency generates a
time reference for energy calculations, the content of
energy registers and also the pulse rate of impulse outputs
will change when crystal is changed. For example, the
nominal meter constant and display pulse rate of 60 Hz
meter (3.93216 MHz clock) is:
MC = 65----00---HH----zz-- × 1250k--i-mW-----p-h-- = 1500k--i-mW-----p-h--
and
The LSB of energy registers correspond to 0.33Wh instead
of 0.4Wh, as follows:
ELSB = 3--3--.-9.--2--3--7-2--6-1--8--6-M--M----H-H---z-z-- × 0.4Wh = 0.333333…Wh
The pulse rate can be scaled to 100 imp/kWh by program-
ming value 5 to MCC coefficient, as below:
IMP = (25 + MCC)i--m--1---p-- × ELSB = 30 i--m--1---p-- × 0.3333…Wh = 10 i-W-m-----hp--
DP = 65----00---HH----zz-- × 100k--i-mW-----p-h-- = 120k--i-mW-----p-h--
which equals 100 impulses per kilowatt hour.
The following table summarizes the contents of all mea-
surement registers.
Register
REG0 - REG2
REG3 - REG5
REG6 - REG8
REG9 - REG11
REG12 - REG15
REG16
REG17
REG19 - 21
REG22 - 24
Conditions
U = 270V, I = 80A, PF = 1
U = 270V, I = 80A, PF = 0
U = 270V, I = 80A
PF = 1
PF = -1
W = 1.718GWh
∆T = 238609.3h
50*T = 40.959s
U = 270V
I = 80A
Full Scale Output (hex)
258F C2F7
2231 594D
258E
7FFF
8001
FFFF FFFF
FFFF FFFF
7FFF
7A8B
7DA4
Resolution (hex)
34.276 µW
37.653 µVAr
2.2467 VA
0.0000305
-0.0000305
0.4Wh
0.2s
1.25 ms
8.6 mV
2.5 mA
11
Share Link: 
