M48T37 ST Microelectronics, M48T37 Datasheet - Page 3

• Manufacturer Part Number: M48T37
• Description: 3.3V-5V 256 Kbit 32Kb x8 TIMEKEEPER SRAM
• Manufacturer: ST Microelectronics

Table 3. Operating Modes
Note: 1. X = V
Figure 3. Block Diagram
Deselect
Write
Read
Read
Deselect
Deselect
Mode
2. See Table 7 for details.
32,768 Hz
CRYSTAL
LITHIUM
IH
CELL
or V
IL
V
; V
SO
SO
4.5V to 5.5V
3.0V to 3.6V
to V
(M48T37Y)
(M48T37V)
= Battery Back-up Switchover Voltage.
V
PFD
V
or
CC
SO
(1)
(min)
OSCILLATOR AND
IRQ/FT
VOLTAGE SENSE
V CC
CLOCK CHAIN
SWITCHING
CIRCUITRY
(2)
AND
WDI
RST
V
V
V
V
E
X
X
IH
IL
IL
IL
POWER
V PFD
V
V
G
X
X
X
X
IH
IL
V
V
V
W
X
X
X
SRAM ARRAY
IH
IH
IL
16 x 8 BiPORT
SRAM ARRAY
32,752 x 8
V SS
DQ0-DQ7
High Z
High Z
High Z
High Z
D
D
OUT
IN
M48T37Y, M48T37V
Battery Back-up Mode
CMOS Standby
Standby
Power
A0-A14
DQ0-DQ7
E
W
G
Active
Active
Active
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