M41T315W-65MH6TR ST Microelectronics, M41T315W-65MH6TR Datasheet - Page 8

• Manufacturer Part Number: M41T315W-65MH6TR
• Description: Serial Access Phantom RTC Supervisor
• Manufacturer: ST Microelectronics

M41T315Y*, M41T315V, M41T315W
Non-volatile Supervisor Operation
A switch is provided to direct power from the bat-
tery input or V
drop of 0.3 Volts. The V
supply uninterrupted power to CMOS SRAM. The
M41T315Y/V/W safeguards the clock and RAM
data by power-fail detection and write protection.
Power-fail detection occurs when V
V
ence. The M41T315Y/V/W constantly monitors
the V
Figure 8. READ Mode Waveforms
Figure 9. WRITE Mode Waveforms
8/24
PFD
CCI
which is set by an internal bandgap refer-
WE
CEI
OE
Q
supply pin. When V
OE
WE
CEI
D
CCI
to V
CCO
tCOE
CCO
with a maximum voltage
CCI
output pin is used to
is less than V
tCO
CCI
tOEE
tWP
falls below
tCW
tOW
tDS
tOE
tCW
PFD
DATA INPUT STABLE
,
DATA OUTPUT VALID
tWC
tRC
power-fail circuitry forces the chip enable output
(
write protection. During nominal supply conditions,
CEO
nally, the M41T315Y/V/W aborts any data transfer
in progress without changing any of the device
registers and prevents future access until V
exceeds V
cal RAM/clock interface.
CEO
) to V
will track
PFD
CCI
tWR
tODO
tRR
tDH
tOD
tWR
.
CEI
or V
t
Figure 7., page 6
DH
with a propagation delay. Inter-
BAT
-0.2 volts for external RAM
illustrates a typi-
AI04259
AI04261
CCI