RTC with Constant-Voltage Trickle Charger
POWER-UP/POWER-DOWN CHARACTERISTICS
(T
A
= -40°C to +85°C) (Note 1)
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
DS12R885/DS12CR887/DS12R887
CAPACITANCE
(T
A
= +25°C)
PARAMETER
Capacitance on All Input Pins
Except X1 and X2
Capacitance on
IRQ,
SQW, and
DQ Pins
SYMBOL
C
IN
C
IO
(Note 9)
(Note 9)
CONDITIONS
MIN
TYP
MAX
10
10
UNITS
pF
pF
AC TEST CONDITIONS
PARAMETER
Input Pulse Levels (-5)
Input Pulse Levels (-33)
Output Load Including Scope and Jig (-5)
Output Load Including Scope and Jig (-33)
Input and Output Timing Measurement Reference Levels
Input-Pulse Rise and Fall Times
0 to 3.0V
0 to 2.7V
50pF + 1TTL Gate
25pF + 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:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
Limits at -40°C are guaranteed by design and not production tested.
All voltages are referenced to ground.
All outputs are open.
Specified with
CS
= DS = R/W =
RESET
= V
CC
; MOT, AS, AD0–AD7 = 0; V
BACKUP
open.
Applies to the AD0 to AD7 pins, the
IRQ
pin, and the SQW pin when each is in a high-impedance state.
The MOT pin has an internal 20kΩ pulldown.
Measured with a 32.768kHz crystal attached to X1 and X2.
Measured with a 50pF capacitance load.
Guaranteed by design. Not production tested.
_____________________________________________________________________
7
DALLAS [ DALLAS SEMICONDUCTOR ]
