DS1230W
7 of 11
POWER-DOWN/POWER-UP TIMING (tA: See Note 10)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
VCC Fail Detect to CE and WE Inactive
t
PD
1.5
µs
11
VCC slew from VTP to 0V t
F
150
µs
VCC slew from 0V to V
TP
t
R
150
µs
VCC Valid to CE and WE Inactive
t
PU
2ms
VCC Valid to End of Write Protection t
REC
125 ms
(tA=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 = VIH or VIL. If OE = VIH during write cycle, the output buffers remain in a high-impedance state.
3. tWP is specified as the logical A ND of CE and WE . tWP is measured from the latter of CE or WE
going low to the earlier of CE or WE going high.
4. tDH, tDS 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 DS1230W has a built-in switch that disconnects the lithium source until VCC is first applied by
the user. The expected tDR is defined as accumulative time in the absence of VCC 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.