Datasheet

M41T81 Clock operation
Doc ID 7529 Rev 10 15/29
The IRQ/FT/OUT/SQW pin is an open drain output which requires a pull-up resistor to V
CC
for proper operation. A 500-10 k resistor is recommended in order to control the rise time.
The FT bit is cleared on power-down.
Figure 10. Crystal accuracy across temperature
Figure 11. Clock calibration
AI07888
–160
0 10203040506070
Frequency (ppm)
Temperature °C
80–10–20–30–40
–100
–120
–140
–40
–60
–80
20
0
–20
= –0.036 ppm/°C
2
± 0.006 ppm/°C
2
K
ΔF
= K x (T – T
O
)
2
F
T
O
= 25°C ± 5°C
AI00594B
NORMAL
POSITIVE
CALIBRATION
NEGATIVE
CALIBRATION