m48t512y STMicroelectronics, m48t512y Datasheet - Page 13

• Manufacturer Part Number: m48t512y
• Description: 5.0 Or 3.3v, 4 Mbit 512 Kbit X 8 Timekeeper Sram
• Manufacturer: STMicroelectronics

Figure 9. Calibration Waveform
V
I
switching, can produce voltage fluctuations, re-
sulting in spikes on the V
can be reduced if capacitors are used to store en-
ergy, which stabilizes the V
stored in the 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 0.1µF is rec-
ommended in order to provide the needed filtering.
In addition to transients that are caused by normal
SRAM operation, power cycling can generate neg-
ative voltage spikes on V
below V
spikes can cause data corruption in the SRAM
while in battery backup mode. To protect from
these voltage spikes, ST recommends connecting
a schottky diode from V
nected to V
1N5817 is recommended for through hole and
MBRS120T3 is recommended for surface mount).
CC
CC
transients, including those produced by output
Noise And Negative Going Transients
NORMAL
POSITIVE
CALIBRATION
NEGATIVE
CALIBRATION
SS
by as much as one volt. These negative
CC
, anode to V
CC
CC
CC
to V
bus. These transients
that drive it to values
SS
CC
). (Schottky diode
SS
bus. The energy
(cathode con-
Figure 10. Supply Voltage Protection
V CC
0.1 F
M48T512Y, M48T512V*
V CC
V SS
DEVICE
AI00594B
AI02169
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