DS1501/DS1511 Y2KC Watchdog Real-Time Clocks
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WAKEUP/KICKSTART TIMING
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Kickstart-Input Pulse Width
tKSPW
2
s
Wakeup/Kickstart Power-On Timeout
tPOTO
(Note 10)
2
s
Note: Time intervals shown above are referenced in Wakeup/Kickstart.
Figure 7. Wakeup/Kickstart Timing Diagram
tKSPW
tPOTO
VCC
CONDITION:
VPF
VBAT
<
VPF
VBAT
0V
VBAT
VPF
0V
VCC
CONDITION:
VBAT
VPF >
TDF/KSF
(INTERNAL)
VIL
VIH
HI-Z
____
IRQ
VIL
VIH
HI-Z
____
PWR
VIH
VIL
___
KS
1
2
3
4
5
INTERVALS
Note 1: Limits at -40°C are not production tested and are guaranteed by design.
Note 2: RTC modules can be successfully processed through conventional wave-soldering techniques as long as temperature exposure to the
lithium energy source contained within does not exceed +85°C. Post-solder cleaning with water-washing techniques is acceptable,
provided that ultrasonic vibration is not used to prevent damage to the crystal.
Note 3: Voltage referenced to ground.
Note 4: Outputs are open.
Note 5: The IRQ, PWR, and RST outputs are open drain.
Note 6: If VPF is less than VBAT and VBAUX, the device power is switched from VCC to the greater of VBAT or VBAUX when VCC drops below VPF. If VPF
is greater than VBAT and VBAUX, the device power is switched from VCC to the greater of VBAT or VBAUX when VCC drops below the greater
of VBAT or VBAUX.
Note 7: VBAT or VBAUX current. Using a 32,768Hz crystal connected to X1 and X2.
Note 8: These parameters are sampled with a 5pF load and are not 100% tested.
Note 9: tDR is the amount of time that the internal battery can power the internal oscillator and internal registers of the DS1511.
Note 10: If the oscillator is not enabled, the startup time of the oscillator after VCC1 is applied will be added to the wakeup/kickstart timeout.
Note 11: Typical values are at +25°C, nominal (active) supply, unless otherwise noted.