M41T00CAPPC1 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

M41T00CAPPC1

Serial access real-time clock (RTC) with integral backup battery and crystal

STMicroelectronics 

Clock operation

M41T00CAP

for correction. Note that setting or changing the calibration byte does not affect the

frequency test output frequency. The FT/OUT pin is an open drain output which requires a

pull-up resistor to VCC for proper operation. A 500-10 kΩ resistor is recommended in order

to control the rise time. The FT bit is cleared on power-down.

Figure 10. Crystal accuracy across temperature

Frequency (ppm)

20

0

–20

–40

–60

–80

–100

–120

ΔF

F

=

K

x

(T

–

TO)2

K = –0.036 ppm/°C2 ± 0.006 ppm/°C2

TO = 25°C ± 5°C

–140

–160

–40 –30 –20 –10 0

10 20 30 40 50 60 70 80

Temperature °C

AI07888

Figure 11. Clock calibration

NORMAL

POSITIVE

CALIBRATION

NEGATIVE

CALIBRATION

AI00594B

4.3

Century bit

Bits D7 and D6 of clock register 02h contain the century enable bit (CEB) and the century bit

(CB). Setting CEB to a '1' will cause CB to toggle, either from a '0' to '1' or from '1' to '0' at

the turn of the century (depending upon its initial state). If CEB is set to a '0,' CB will not

toggle.

16/27

Doc ID 14557 Rev 5

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