R
A3024
Typical Standby Current at V
DD
= 5 V
I
DD
[
m
A]
5
4
3
2
1
0
-50
25
50
80
95
T
A
[ C]
Fig. 3
0
Typical standby current range at V
DD
= 5 V
Typical Frequency on IRQ
DF
ppm
F
0
250
200
150
100
50
0
-50
-30
-10
10
30
50
70
90
Address 10 hex = 00 hex
Quartz recommended
32.768 Hz ± 30 ppm
with 8.2 pF load capacitance
T
A
[
0
C]
Fig. 4
Characteristic of a Quartz
DF
F
0
[ppm]
-100
DF
ppm
2
= - 0.038
O
2
(T - T
O
) ±10%
F
O
C
DF/F
O
= the ratio of the change in frequency to the nominal value
expressed in ppm (It can be thought of as the frequency
deviation at any temperature.)
O
= the temperature of interest in C
T
O
T
O
= the turnover temperature (25 ±5 C)
To determine the clock error (accuracy) at a given temperature, add
O
the frequency tolerance at 25 C to the value obtained from the
formula above.
T
O
-100
T
O
- 50
T
O
O
Frequency ratio [ppm]
ma
x.
-200
-300
-400
T
O
+50
Temperature [ C]
T
O
+100
T [
O
C]
min
.
Fig. 5
3
EMMICRO [ EM MICROELECTRONIC - MARIN SA ]
