The M48Z58/Y ZEROPOWER® RAM is an 8 Kbit x 8 non-volatile static RAM that integrates
power-fail deselect circuitry and battery control logic on a single die. The monolithic chip is
available in two special packages to provide a highly integrated battery-backed memory
solution.
The M48Z58/Y is a non-volatile pin and function equivalent to any JEDEC standard 8 K x 8
SRAM. It also easily fits into many ROM, EPROM, and EEPROM sockets, providing the
non-volatility of PROMs without any requirement for special WRITE timing or limitations on
the number of WRITEs that can be performed.
The 28-pin, 600 mil DIP CAPHAT
button cell in a single package.
™
houses the M48Z58/Y silicon with a long life lithium
The 28-pin, 330 mil SOIC provides sockets with gold plated contacts at both ends for direct
connection to a separate SNAPHAT
®
housing containing the battery. The unique design
allows the SNAPHAT battery package to be mounted on top of the SOIC package after the
completion of the surface mount process. Insertion of the SNAPHAT housing after reflow
prevents potential battery damage due to the high temperatures required for device surfacemounting. The SNAPHAT housing is keyed to prevent reverse insertion.
The SOIC and battery packages are shipped separately in plastic anti-static tubes or in tape
& reel form.
For the 28-lead SOIC, the battery package (e.g., SNAPHAT) part number is “M4Z28BR00SH1”.
Figure 1.Logic diagram
V
CC
A0-A12
W
13
M48Z58
M48Z58Y
E
8
DQ0-DQ7
G
V
SS
Doc ID 2559 Rev 115/24
AI01176B
DescriptionM48Z58, M48Z58Y
Table 1.Signal names
A0-A12Address inputs
DQ0-DQ7Data inputs / outputs
EChip enable input
GOutput enable input
WWRITE enable input
V
CC
V
SS
NCNot connected internally
Figure 2.DIP connections
Supply voltage
Ground
NCV
1
A12
2
A7
3
A6
4
A5
5
A4
6
A3
7
8
9
10
11
M48Z58
M48Z58Y
A2
A1
A0
DQ0
12
DQ2
13
14
SS
28
27
26
25
24
23
22
21
20
19
18
17
16
15
CC
W
NC
A8
A9
A11
G
A10
E
DQ7
DQ6
DQ5DQ1
DQ4
DQ3V
AI01177B
Figure 3.SOIC connections
NCV
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ2
SS
6/24Doc ID 2559 Rev 11
1
2
3
4
5
6
7
8
9
10
11
12
13
14
M48Z58Y
28
27
26
25
24
23
22
21
20
19
18
17
16
15
CC
W
NC
A8
A9
A11
G
A10
E
DQ7
DQ6
DQ5DQ1
DQ4
DQ3V
AI01178B
M48Z58, M48Z58YDescription
Figure 4.Block diagram
A0-A12
LITHIUM
CELL
VOLTAGE SENSE
AND
SWITCHING
CIRCUITRY
V
CC
POWER
V
PFD
8K x 8
SRAM ARRAY
V
SS
DQ0-DQ7
E
W
G
AI01394
Doc ID 2559 Rev 117/24
Operating modesM48Z58, M48Z58Y
2 Operating modes
The M48Z58/Y also has its own power-fail detect circuit. The control circuitry constantly
monitors the single 5 V supply for an out of tolerance condition. When V
tolerance, the circuit write protects the SRAM, providing a high degree of data security in the
midst of unpredictable system operation brought on by low V
switchover voltage (V
), the control circuitry connects the battery which maintains data
SO
. As VCC falls below battery
CC
until valid power returns.
Table 2.Operating modes
ModeV
Deselect
WRITEV
READV
READV
DeselectV
Deselect≤ V
1. See Table 10 on page 16 for details.
SO
CC
4.75 to 5.5 V
or
4.5 to 5.5 V
to V
PFD
SO
(min)
(1)
(1)
EGWDQ0-DQ7Power
V
XXXHigh ZCMOS standby
XXXHigh ZBattery backup mode
XXHigh ZStandby
IH
XVILD
IL
V
IL
V
IL
V
IL
IH
IH
V
IH
IN
D
OUT
High ZActive
is out of
CC
Active
Active
Note:X = V
or VIL; VSO = Battery backup switchover voltage.
IH
2.1 READ mode
The M48Z58/Y is in the READ mode whenever W (WRITE enable) is high, E (chip enable) is
low. Thus, the unique address specified by the 13 address inputs defines which one of the
8,192 bytes of data is to be accessed. Valid data will be available at the data I/O pins within
address access time (t
and G
access times are also satisfied. If the E and G access times are not met, valid data
will be available after the latter of the chip enable access time (t
access time (t
The state of the eight three-state data I/O signals is controlled by E
activated before t
the address inputs are changed while E
for output data hold time (t
GLQV
) after the last address input signal is stable, providing that the E
AVQ V
) or output enable
ELQV
).
and G. If the outputs are
, the data lines will be driven to an indeterminate state until t
AVQ V
and G remain active, output data will remain valid
) but will go indeterminate until the next address access.
AXQX
AVQ V
. If
8/24Doc ID 2559 Rev 11
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