DS1220Y
6 of 8
POWER-DOWN/POWER-UP CONDITION
SEE NOTE 11
POWER-DOWN/POWER-UP TIMING
PARAMETER SYMBOL MIN MAX UNITS NOTES
CE
at V
IH
before Power-Down
t
PD
0
μs
11
V
CC
Slew from V
TP
to 0V t
F
100
μs
V
CC
Slew from 0V to V
TP
t
R
0
μs
CE at V
IH
after Power-Up
t
REC
2 ms
(T
A
= 25°C)
PARAMETER SYMBOL MIN MAX UNITS NOTES
Expected Data Retention Time t
DR
10 years 9
WARNING:
Under no circumstance are negative undershoots, of any amplitude, allowed when device is in battery
backup mode.
NOTES:
1. WE is high for a read cycle.
2. OE = V
IH
or V
IL
. If OE = V
IH
during a write cycle, the output buffers remain in a high impedance
state.
3. t
WP
is specified as the logical AND of
CE
and
WE
. t
WP
is measured from the latter of
CE
or
WE
going low to the earlier of
CE or WE going high.
4. t
DS
are measured from the earlier of CE or WE going high.
5. These parameters are sampled with a 5 pF load and are not 100% tested.
6. If the
CE
low transition occurs simultaneously with or later than the
WE
low transition in write
cycle 1, the output buffers remain in a high impedance state during this period.
