Datasheet

DS1230Y/AB
8 of 12
POWER-DOWN/POWER-UP TIMING (t
A
: See Note 10)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
CE, at V
IH
before Power-Down t
PD
0
µs
11
V
CC
slew from V
TP
to 0V (CE at V
IH
)
t
F
300
µs
V
CC
slew from 0V to V
TP
(CE at V
IH
)
t
R
300
µs
CE at V
IH
after Power-Up
t
REC
2 125 ms
(t
A
=25°C)
PARAMETER SYMBOL MIN TYP 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 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
DH
, 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 latter than the WE low transition, the output
buffers remain in a high-impedance state during this period.
7. If the CE high transition occurs prior to or simultaneously with the WE high transition, the output
buffers remain in high-impedance state during this period.
8. If
WE is low or the WE low transition occurs prior to or simultaneously with the CE low transition,
the output buffers remain in a high-impedance state during this period.
9. Each DS1230Y has a built-in switch that disconnects the lithium source until V
CC
is first applied by
the user. The expected t
DR
is defined as accumulative time in the absence of V
CC
starting from the
time power is first applied by the user.
10. All AC and DC electrical characteristics are valid over the full operating temperature range. For
commercial products, this range is 0°C to 70°C. For industrial products (IND), this range is -40°C to
+85°C.
11. In a power-down condition the voltage on any pin may not exceed the voltage on V
CC
.
12. t
WR1
and t
DH1
are measured from WE going high.
13. t
WR2
and t
DH2
are measured from CE going high.
14. DS1230 DIP modules are recognized by Underwriters Laboratory (U.L.) under file E99151.
DS1230 PowerCap modules are pending U.L. review. Contact the factory for status.