
DS1557 4Meg, Nonvolatile, Y2K-Compliant Timekeeping RAM
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POWER-UP/DOWN CHARACTERISTICS—5V
(VCC = 5.0V ±10%, TA = Over the Operating Range.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
CE or WE at V
IH, Before
Power-Down
tPD
0
s
VCC Fall Time: VPF(MAX) to VPF(MIN)
tF
300
s
VCC Fall Time: VPF(MIN) to VSO
tFB
10
s
VCC Rise Time: VPF(MIN) to VPF(MAX)
tR
0
s
VPF to RST High
tREC
40
200
ms
Expected Data-Retention Time
(Oscillator On)
tDR
(Note 6)
10
years
Figure 8. Power-Up/Down Waveform Timing—5V Device