DS1685/DS1687 3V/5V Real-Time Clocks
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POWER-UP/DOWN TIMING—5V
(TA = +25°C)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
CS
High to Power-Fail
tPF
0
ns
Recovery at Power-Up
tREC
150
ms
VCC Slew Rate Power-Down
tF
4.0 ≤ VCC ≤ 4.5V
300
s
VCC Slew Rate Power-Down
tFB
3.0 ≤ VCC ≤ 4.0V
10
s
VCC Slew Rate Power-Up
tR
4.5V ≥ VCC ≥ 4.0V
0
s
Expected Data Retention
tDR
10
years
9, 10
POWER-UP/DOWN TIMING—3V
(TA = +25°C)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
CS
High to Power-Fail
tPF
0
ns
Recovery at Power-Up
tREC
150
ms
VCC Slew Rate Power-Down
tF
2.5 ≤ VCC ≤ 2.7V
300
s
VCC Slew Rate Power-Up
tR
2.7V ≥ VCC ≥ 2.5V
0
s
Expected Data Retention
tDR
10
years
9, 10
WARNING: Under no circumstances are negative undershoots, of any amplitude, allowed
when device is in battery-backup mode.
CAPACITANCE
(TA = +25°C)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
Input Capacitance on All Inputs
Except X1 and X2
CIN
12
pF
Output Capacitance on IRQ,
SQW and DQ pins
COUT
12
pF
WAKE-UP/KICKSTART TIMING
(TA = +25°C)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
Kickstart Input Pulse Width
tKSPW
2
s
Wake-Up/Kickstart Power On
Timeout
tPOTO
2
seconds
7