M40Z300AVMH1E STMICROELECTRONICS [STMicroelectronics], M40Z300AVMH1E Datasheet - Page 4

• Manufacturer Part Number: M40Z300AVMH1E
• Description: 3V NVRAM Supervisor for Up to 8 LPSRAMs
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M40Z300AV
DESCRIPTION
The M40Z300AV NVRAM SUPERVISOR is a self-
contained device which converts a standard low-
power SRAM into a non-volatile memory. A preci-
sion voltage reference and comparator monitors
the V
When an invalid V
tioned chip enable outputs (E1
forced inactive to write-protect the stored data in
the SRAM. During a power failure, the SRAM is
switched from the V
the SNAPHAT
data retention. On a subsequent power-up, the
SRAM remains write protected until a valid power
condition returns.
The 28-pin, 330mil SOIC provides sockets with
gold plated contacts for direct connection to a sep-
arate 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 im-
proper insertion. This unique design allows the
SNAPHAT battery package to be mounted on top
Figure 3. Logic Diagram
Note: 1. For 16-pin SOIC package only.
4/20
THS
2. THS pin must be connected to V
CC
input for an out-of-tolerance condition.
(2)
E
B
A
®
to provide the energy required for
CC
V CC
M40Z300AV
V SS
CC
condition occurs, the condi-
pin to the lithium cell within
B+
B–
(1)
(1)
CON
SS
.
to E4
V OUT
BL
E1 CON
E2 CON
E3 CON
E4 CON
RST
AI08893
CON
) are
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 sol-
dered 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-mount-
ing. The SNAPHAT housing is also keyed to pre-
vent 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 bat-
tery/crystal package (e.g., SNAPHAT) part num-
ber
13., page
Caution: Do not place the SNAPHAT battery top
in conductive foam, as this will drain the lithium
button-cell battery.
Table 1. Signal Names
Note: 1. THS pin must be connected to V
THS
E
E1
A, B
RST
BL
V
V
V
B +
B –
NC
OUT
CC
SS
CON
2. For M40Z300AV, B– must be connected to the negative
(2)
(1)
is
battery terminal only (not to Pin 8, V
- E4
18).
CON
“M4ZXX-BR00SH”
Threshold Select Input
Chip Enable Input
Conditioned Chip Enable
Output
Decoder Inputs
Reset Output (Open Drain)
Battery Low Output (Open
Drain)
Supply Voltage Output
Supply Voltage
Ground
Positive Battery Pin
Negative Battery Pin
Not Connected Internally
SS
.
SS
(see
).
Table