DS12885_10 Datasheet, PDF (6/22 Pages) Maxim Integrated Products – Real-Time Clocks

Real-Time Clocks
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)
SYMBOL
t_RPU
t_F
CONDITIONS
V_CC Rise Time; V_PF(MIN) to
V_PF(MAX)
t_R
DATA RETENTION
(T_A = +25°C)
PARAMETER
Expected Data Retention
SYMBOL
t_DR
CONDITIONS
MIN TYP MAX UNITS
20
200
ms
300
µs
0
µs
MIN TYP MAX UNITS
10
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 UNITS
5
pF
7
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
TEST CONDITIONS
0 to 3.0V
50pF + 1TTL Gate
Input/Output: V_IL maximum and V_IH minimum
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_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.
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