m48z18 STMicroelectronics, m48z18 Datasheet - Page 4

• Manufacturer Part Number: m48z18
• Description: 5v, 64 Kbit 8kb X 8 Zeropower Sram
• Manufacturer: STMicroelectronics

M48Z08, M48Z18
Figure 4. Block Diagram
OPERATION MODES
The M48Z08/18 also has its own Power-fail Detect
circuit. The control circuitry constantly monitors
the single 5V supply for an out of tolerance condi-
tion. When V
protects the SRAM, providing a high degree of
Table 2. Operating Modes
Note: X = V
4/16
Deselect
WRITE
READ
READ
Deselect
Deselect
Mode
1. See
IH
LITHIUM
Table 10., page 12
or V
CELL
V
CC
SO
IL
; V
4.75 to 5.5V
is out of tolerance, the circuit write
4.5 to 5.5V
to V
SO
V
V
= Battery Back-up Switchover Voltage.
PFD
or
SO
CC
(1)
(min)
for details.
(1)
VOLTAGE SENSE
SWITCHING
CIRCUITRY
AND
V CC
V
V
V
V
E
X
X
IH
IL
IL
IL
V
V
G
X
X
X
X
IH
IL
POWER
V PFD
data security in the midst of unpredictable system
operation brought on by low V
low approximately 3V, the control circuitry con-
nects the battery which maintains data until valid
power returns.
V
V
V
W
X
X
X
IH
IH
IL
SRAM ARRAY
8K x 8
DQ0-DQ7
V SS
High Z
High Z
High Z
High Z
D
D
OUT
IN
Battery Back-up Mode
CMOS Standby
CC
Standby
. As V
Power
Active
Active
Active
A0-A12
DQ0-DQ7
E
W
G
AI01394
CC
falls be-