M41T82_10 Datasheet, PDF (30/61 Pages) STMicroelectronics – Serial I2C bus RTC with battery switchover

Clock operation
M41T82-M41T83
Figure 17. Crystal accuracy across temperature
Frequency (ppm)
20
0
–20
–40
–60
–80
–100
–120
ΔF
F
=
K
x
(T
–
T_O)²
K = –0.036 ppm/°C² ± 0.006 ppm/°C²
T_O = 25°C ± 5°C
–140
–160
–40 –30 –20 –10 0
10 20 30 40 50 60 70 80
Temperature °C
AI07888
Table 7. Analog calibration values
Analog
calibration D7 D6
D5 D4 D3 D2
D1
value
Addr
D0
C_XI, C_XO C_LOAD(1)
ACS AC6 AC5 AC4 AC3 AC2 AC1
AC0
(±) (16 pF) (8 pF) (4 pF) (2 pF) (1 pF) (0.5 pF) (0.25 pF)
½(C_XI, C_XO)
0 pF
x
0
0
0
0
0
0
3 pF
0
0
0
0
1
1
0
5 pF
0
0
0
1
0
1
0
12h
–7 pF
1
0
0
1
1
1
0
9.75 pF⁽²⁾ 0
0
1
0
0
1
1
–18 pF⁽³⁾ 1
1
0
0
1
0
0
0
25 pF 12.5 pF
0
28 pF
14 pF
0
30 pF
15 pF
0
18 pF
9 pF
1
34.75 pF 17.4 pF
0
7 pF
3.5 pF
1. C_LOAD = 1/(1/C_XI + 1/C_XO).
2. Maximum negative calibration value.
3. Maximum positive calibration value.
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Doc ID 12578 Rev 12