Real-Time Clock
POWER-UP/POWER-DOWN CHARACTERISTICS
(T = -40°C to +85°C) (Note 2)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Recovery at Power-Up
t
20
200
ms
RPU
V
V
Fall Time; V
PF(MIN)
to
to
CC
PF(MAX)
t
300
0
µs
µs
F
V
V
Rise Time; V
PF(MIN)
PF(MAX)
CC
t
R
DATA RETENTION
(T = +25°C)
A
PARAMETER
SYMBOL
CONDITIONS
CONDITIONS
MIN
TYP
TYP
MAX
UNITS
Expected Data Retention
t
10
years
DR
CAPACITANCE
(T = +25°C) (Note 9)
A
PARAMETER
SYMBOL
MIN
MAX
UNITS
Capacitance on All Input Pins
Except X1 and X2
C
C
5
pF
IN
IO
Capacitance on IRQ, SQW, and
DQ Pins
7
pF
AC TEST CONDITIONS
PARAMETER
TEST CONDITIONS
Input Pulse Levels
0 to 3.0V
Output Load Including Scope and Jig
50pF + 1TTL Gate
Input and Output Timing Measurement Reference Levels
Input-Pulse Rise and Fall Times
Input/Output: V maximum and V minimum
IL IH
5ns
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 ; MOT, AS, AD0–AD7 = 0; V
open.
CC
BACKUP
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.
5/DS12C87A
Note 10: Measured with a 50pF capacitance load.
6
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
