m40z111 STMicroelectronics, m40z111 Datasheet - Page 5

• Manufacturer Part Number: m40z111
• Description: 5v Or 3v Nvram Supervisor For Up To Two Lpsrams
• Manufacturer: STMicroelectronics

1
Description
The M40Z111/W NVRAM supervisor is a self-contained device which converts a standard
low-power SRAM into a non-volatile memory.
A precision voltage reference and comparator monitors the V
condition.
When an invalid V
inactive to write-protect the stored data in the SRAM.
During a power failure, the SRAM is switched from the V
SNAPHAT
the SRAM remains write protected until a valid power condition returns.
The 28-pin, 330mil 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 surface-mounting. 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
“M4Z28-BR00SH1” or “M4Z32-BR00SH1” (See
Figure 1.
®
to provide the energy required for data retention. On a subsequent power-up,
Logic diagram
CC
condition occurs, the conditioned chip enable (E
THS
E
V CC
M40Z111W
V SS
M40Z111
Table 11 on page
CC
V OUT
E CON
pin to the lithium cell within the
CC
AI02238B
input for an out-of-tolerance
19).
CON
) output is forced
5/21