Real-Time Clock
DS12885/DS12887/DS12887A/DS12C887/DS12C887A
POWER-UP/POWER-DOWN CHARACTERISTICS
(T
A
= -40°C to +85°C) (Note 2)
PARAMETER
Recovery at Power-Up
V
CC
Fall Time; V
PF(MAX)
to
V
PF(MIN)
V
CC
Rise Time; V
PF(MIN)
to
V
PF(MAX)
SYMBOL
t
RPU
t
F
t
R
CONDITIONS
MIN
20
300
0
TYP
MAX
200
UNITS
ms
µs
µs
DATA RETENTION
(T
A
= +25°C)
PARAMETER
Expected Data Retention
SYMBOL
t
DR
CONDITIONS
MIN
10
TYP
MAX
UNITS
years
CAPACITANCE
(T
A
= +25°C) (Note 9)
PARAMETER
Capacitance on All Input Pins
Except X1 and X2
Capacitance on
IRQ,
SQW, and
DQ Pins
SYMBOL
C
IN
C
IO
CONDITIONS
MIN
TYP
MAX
5
7
UNITS
pF
pF
AC TEST CONDITIONS
PARAMETER
Input Pulse Levels
Output Load Including Scope and Jig
Input and Output Timing Measurement Reference Levels
Input-Pulse Rise and Fall Times
0 to 3.0V
50pF + 1TTL Gate
Input/Output: V
IL
maximum and V
IH
minimum
5ns
TEST CONDITIONS
WARNING:
Negative undershoots below -0.3V while the part is in battery-backed mode may cause loss of data.
Note 1:
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. However, post-solder cleaning with water-
washing techniques is acceptable, provided that ultrasonic vibrations are not used to prevent crystal damage.
Note 2:
Limits at -40°C are guaranteed by design and not production tested.
Note 3:
All voltages are referenced to ground.
Note 4:
All outputs are open.
Note 5:
Specified with
CS
= DS = R/W =
RESET
= V
CC
; MOT, AS, AD0–AD7 = 0; V
BACKUP
open.
Note 6:
Applies to the AD0 to AD7 pins, the
IRQ
pin, and the SQW pin when each is in a high-impedance state.
Note 7:
The MOT pin has an internal 20kΩ pulldown.
Note 8:
Measured with a 32.768kHz crystal attached to X1 and X2.
Note 9:
Guaranteed by design. Not production tested.
Note 10:
Measured with a 50pF capacitance load.
6
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
