m48t201y STMicroelectronics, m48t201y Datasheet - Page 26

• Manufacturer Part Number: m48t201y
• Description: 3.3v-5v Timekeeper Controller
• Manufacturer: STMicroelectronics

Clock operation
3.13
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V
I
fluctuations, resulting in spikes on the V
capacitors are used to store energy which stabilizes the V
bypass capacitors will be released as low going spikes are generated or energy will be
absorbed when overshoots occur. A ceramic bypass capacitor value of 0.1 µF (as shown in
Figure
In addition to transients that are caused by normal SRAM operation, power cycling can
generate negative voltage spikes on V
one volt. These negative spikes can cause data corruption in the SRAM while in battery
backup mode. To protect from these voltage spikes, STMicroelectronics recommends
connecting a schottky diode from V
Schottky diode 1N5817 is recommended for through hole and MBRS120T3 is
recommended for surface mount.
Figure 12. Supply voltage protection
CC
CC
transients, including those produced by output switching, can produce voltage
noise and negative going transients
12) is recommended in order to provide the needed filtering.
V CC
0.1 F
CC
CC
to V
CC
that drive it to values below V
SS
bus. These transients can be reduced if
(cathode connected to V
V CC
V SS
DEVICE
CC
bus. The energy stored in the
AI00605
M48T201Y, M48T201V
CC
SS
, anode to V
by as much as
SS
).