M48T08 ST Microelectronics, M48T08 Datasheet - Page 14

• Manufacturer Part Number: M48T08
• Description: 64 Kbit 8Kb x 8 TIMEKEEPER SRAM
• Manufacturer: ST Microelectronics

M48T08, M48T18
POWER SUPPLY DECOUPLING and UNDER-
SHOOT PROTECTION
I
switching, can produce voltage fluctuations, result-
ing in spikes on the V
be reduced if capacitors are used to store energy,
which stabilizes the V
the bypass capacitors will be released as low going
spikes are generated or energy will be absorbed
when overshoots occur. A ceramic bypass capaci-
tor value of 0.1 F (as shown in Figure 12) is
recommended in order to provide the needed filter-
ing.
In addition to transients that are caused by normal
SRAM operation, power cycling can generate
negative voltage spikes on V
values below V
negative spikes can cause data corruption in the
SRAM while in battery backup mode. To protect
from these voltage spikes, it is recommeded to
connect a schottky diode from V
connected to V
1N5817 is recommended for through hole and
MBRS120T3 is recommended for surface mount.
14/19
CC
transients, including those produced by output
SS
CC
, anode to V
by as much as one Volt. These
CC
CC
bus. These transients can
bus. The energy stored in
SS
CC
CC
). Schottky diode
to V
that drive it to
SS
(cathode
Figure 12. Supply Voltage Protection
V CC
0.1 F
V CC
V SS
DEVICE
AI02169