m48t18 STMicroelectronics, m48t18 Datasheet - Page 5

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

Summary description
The M48T08/18/08Y TIMEKEEPER
time clock which is pin and functional compatible with the DS1643. The monolithic chip is
available in two special packages to provide a highly integrated battery backed-up memory
and real time clock solution.
The M48T08/18/08Y is a non-volatile pin and function equivalent to any JEDEC standard 8K
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, 600mil DIP CAPHAT™ houses the M48T08/18/08Y silicon with a quartz crystal
and a long- life lithium button cell in a single package.
The 28-pin, 330mil SOIC provides sockets with gold plated contacts at both ends for direct
connection to a separate SNAPHAT
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 and crystal damage due to the high
temperatures required for device surface-mounting. The SNAPHAT housing is keyed to
prevent reverse insertion.
The SOIC and battery/crystal packages are shipped separately in plastic anti-static tubes or
in Tape & Reel form. For the 28 lead SOIC, the battery/crystal package (e.g., SNAPHAT)
part number is “M4T28-BR12SH” or “M4T32-BR12SH” (see
Figure 1.
Logic diagram
A0-A12
E1
E2
W
G
13
®
®
RAM is an 8K x 8 non-volatile static RAM and real
housing containing the battery and crystal. The
V CC
V SS
M48T08Y
M48T08
M48T18
8
DQ0-DQ7
INT
Table 17 on page
AI01020
28).
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