m48t18 STMicroelectronics, m48t18 Datasheet - Page 12

• Manufacturer Part Number: m48t18
• Description: 5v, 64kbit 8 Kb X 8 Timekeeper Sram
• Manufacturer: STMicroelectronics

Table 4.
1. Valid for ambient operating temperature: T
Data retention mode
Note:
12/30
Symbol
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
E1LE1H
E2HE2L
t
t
t
t
t
E1HAX
DVE1H
E1HDX
t
AVE2H
E2LAX
E2LDX
AVE1H
WHQX
AVE1L
WLWH
WHAX
DVWH
DVE2L
WHDX
AVE2L
WLQZ
AVWH
AVWL
AVAV
Write mode AC characteristics
With valid V
RAM. Should the supply voltage decay, the RAM will automatically power-fail deselect, write
protecting itself when V
become high impedance, and all inputs are treated as “Don't care.”
A power failure during a WRITE cycle may corrupt data at the currently addressed location,
but does not jeopardize the rest of the RAM's content. At voltages below V
user can be assured the memory will be in a write protected state, provided the V
is not less than t
reach into the deselect window during the time the device is sampling V
decoupling of the power supply lines is recommended.
WRITE Cycle Time
Address Valid to WRITE Enable Low
Address Valid to Chip Enable 1 Low
Address Valid to Chip Enable 2 High
WRITE Enable Pulse Width
Chip Enable 1 Low to Chip Enable 1 High
Chip Enable 2 High to Chip Enable 2 Low
WRITE Enable High to Address Transition
Chip Enable 1 High to Address Transition
Chip Enable 2 Low to Address Transition
Input Valid to WRITE Enable High
Input Valid to Chip Enable 1 High
Input Valid to Chip Enable 2 Low
WRITE Enable High to Input Transition
Chip Enable 1 High to Input Transition
Chip Enable 2 Low to Input Transition
WRITE Enable Low to Output Hi-Z
Address Valid to WRITE Enable High
Address Valid to Chip Enable 1 High
Address Valid to Chip Enable 2 Low
WRITE Enable High to Output Transition
CC
applied, the M48T08/18/08Y operates as a conventional BYTEWIDE™ static
F
Parameter
. The M48T08/18/08Y may respond to transient noise spikes on V
CC
A
= 0 to 70°C; V
(1)
falls within the V
CC
= 4.75 to 5.5V or 4.5 to 5.5V (except where noted).
PFD
–100/–10 (T08Y)
(max), V
Min
100
80
80
80
10
10
10
50
50
50
80
80
80
10
0
0
0
5
5
5
M48T08/M48T18/T08Y
PFD
Max
50
(min) window. All outputs
–150/–15 (T08Y)
Min
150
100
130
130
130
130
130
10
10
10
70
70
70
10
0
5
5
0
0
5
CC
. Therefore,
PFD
Max
70
(min), the
CC
CC
fall time
Unit
that
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns