M40Z300, M40Z300W

Description

Doc ID 5679 Rev 5

5/25

1

Description

The M40Z300/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

provide the energy required for data retention. On a subsequent power-up, the SRAM

remains write protected until a valid power condition returns.

The 28-pin, 330 mil SOIC provides sockets with gold plated contacts for direct connection to

a separate SNAPHAT housing containing the battery. The SNAPHAT housing has gold

plated pins which mate with the sockets, ensuring reliable connection. The housing is keyed

to prevent improper insertion. This unique design allows the SNAPHAT battery package to

be mounted on top of the SOIC package after the completion of the surface mount process

which greatly reduces the board manufacturing process complexity of either directly

soldering or inserting a battery into a soldered holder. Providing non-volatility becomes a

“SNAP.” The 16-pin SOIC provides battery pins for an external user-supplied battery.

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 also

keyed to prevent reverse insertion.

The 28-pin SOIC and battery 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 “M4ZXX-BR00SH”.

Caution:

Do not place the SNAPHAT battery top in conductive foam, as this will drain the lithium

button-cell battery.