DS12R885/DS12CR887/DS12R887
RTCs with Constant-Voltage Trickle Charger
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POWER-UP/POWER-DOWN CHARACTERISTICS
(T
A
= -40°C to +85°C) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Recovery at Power-Up t
RPU
20 200 ms
V
CC
Fall Time; V
PF(MAX)
to
V
PF(MIN)
t
F
300 µs
V
CC
Rise Time; V
PF(MIN)
to
V
PF(MAX)
t
R
0µs
CAPACITANCE
(T
A
= +25°C)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Capacitance on All Input Pins
Except X1 and X2
C
IN
(Note 9) 10 pF
Capacitance on IRQ, SQW, and
DQ Pins
C
IO
(Note 9) 10 pF
DATA RETENTION (DS12CR887)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Expected Data Retention t
DR
T
A
= +25°C 5 Years
PARAMETER TEST CONDITIONS
Input Pulse Levels (-5) 0 to 3.0V
Input Pulse Levels (-33) 0 to 2.7V
Output Load Including Scope and Jig (-5) 50pF + 1TTL Gate
Output Load Including Scope and Jig (-33) 25pF + 1TTL Gate
Input and Output Timing Measurement Reference Levels Input/Output: V
IL
maximum and V
IH
minimum
Input-Pulse Rise and Fall Times 5ns
WARNING: Negative undershoots below -0.3V while the part is in battery-backed mode may cause loss of data.
Note 1: Limits at -40°C are guaranteed by design and not production tested.
Note 2: All voltages are referenced to ground.
Note 3: All outputs are open.
Note 4: Specified with CS = DS = R/W = RESET = V
CC
; MOT, AS, AD0–AD7 = 0; V
BACKUP
open.
Note 5: Applies to the AD0 to AD7 pins, the IRQ pin, and the SQW pin when each is in a high-impedance state.
Note 6: The MOT pin has an internal 20kΩ pulldown.
Note 7: Measured with a 32.768kHz crystal attached to X1 and X2.
Note 8: Measured with a 50pF capacitance load.
Note 9: Guaranteed by design. Not production tested.
