M48T08 ST Microelectronics, M48T08 Datasheet - Page 5

• Manufacturer Part Number: M48T08
• Description: 64 Kbit 8Kb x 8 TIMEKEEPER SRAM
• Manufacturer: ST Microelectronics

Table 8. Power Down/Up Mode AC Characteristics
(T
Notes: 1. V
Figure 5. Power Down/Up Mode AC Waveforms
Note: Inputs may or may not be recognized at this time. Caution should be taken to keep E1 high or E2 low as V
Some systems may perform inadvertent write cycles after V
though a power on reset is being applied to the processor, a reset condition may not occur until after the system clock is runn ing.
A
Symbol
= 0 to 70 C)
t
t
PFH
t
FB
t
t
t
t
REC
F
PFX
2. V
3. INT may go high anytime after V
t
PD
RB
R
(1)
(2)
(3)
V
PFD
CC
PFD
V CC
V PFD (max)
V PFD (min)
V SO
INT
INPUTS
OUTPUTS
passes V
(max) to V
(min) to V
E1 or W at V
V
V
V
V
E1 or W at V
INT Low to Auto Deselect
V
PFD
PFD
PFD
SO
PFD
PFD
to V
(min) to V
SO
(max) to V
(min) to V
(max) to INT High
PFD
tPD
(min).
fall time of less than t
PFD
(min) fall time of less than t
(PER CONTROL INPUT)
(min) V
VALID
IH
IH
RECOGNIZED
PFD
or E2 at V
SO
or E2 at V
PFD
tF
V
(max) V
(min) V
CC
CC
CC
exceeds V
Fall Time
Rise Time
IL
IL
FB
Parameter
CC
CC
tPFX
before Power Down
after Power Up
may cause corruption of RAM data.
Rise Time
tFB
Fall Time
PFD
F
may result in deselection/write protection not occurring until 200 s after
(min) and is guaranteed to go high t
CC
rises above V
tDR
PFD
(min) but before normal system operations begin. Even
DON'T CARE
HIGH-Z
tRB
PFH
after V
Min
300
10
10
0
0
1
1
CC
NOTE
exceeds V
tR
CC
(PER CONTROL INPUT)
M48T08, M48T18
Max
rises past V
120
tPFH
40
tREC
RECOGNIZED
PFD
VALID
(max).
AI00566
PFD
(min).
Unit
ms
s
s
s
s
s
s
s
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