M41T93_08 Datasheet, PDF (39/51 Pages) STMicroelectronics – Serial SPI bus RTC with battery switchover

M41T93
DC and AC parameters
Figure 17. I_CC2 vs. temperature
10.000
9.000
8.000
7.000
6.000
5.000
(3.0V)
(5.0V)
4.000
3.000
2.000
-40
-20
0
20
40
60
80
Temperature (˚C)
ai 13909
Table 19. Crystal electrical characteristics
Symbol
Parameter⁽¹⁾⁽²⁾
Min
Typ
Max
Units
f_O Resonant frequency
R_S Series resistance
32.768
kHz
65⁽³⁾
kΩ
C_L Load capacitance
12.5
pF
1. Externally supplied if using the QFN16 package. STMicroelectronics recommends the Citizen CFS-145
(1.5 x 5 mm) and the KDS DT-38 (3 x 8 mm) for thru-hole, or the KDS DMX-26S (3.2 x 8 mm) or Micro
Crystal MS3V-T1R (1.5 x 5 mm) for surface-mount, tuning fork-type quartz crystals. For contact
information, see Section 8: References on page 49.
2. Load capacitors are integrated within the M41T93. Circuit board layout considerations for the 32.768 kHz
crystal of minimum trace lengths and isolation from RF generating signals should be taken into account.
3. Guaranteed by design.
Table 20. Oscillator characteristics
Symbol
Parameter⁽¹⁾⁽²⁾
Conditions Min Typ Max Units
V_STA Oscillator start voltage
≤4 s
2.0
V
t_STA
Oscillator start time
V_CC = V_SO
1
s
C_XI, C_XO(1) Capacitor input, capacitor output
25
pF
IC-to-IC frequency variation⁽²⁾⁽³⁾
–10
+10 ppm
1. With default analog calibration value ( = 0)
2. Reference value
3. T_A = 25°C, V_CC = 5.0 V
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