M48Z2M1YPL Ver la hoja de datos (PDF) - STMicroelectronics
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M48Z2M1YPL Datasheet PDF : 12 Pages
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M48Z2M1, M48Z2M1Y
Table 10. Write Mode AC Characteristics
(TA = 0 to 70°C; VCC = 4.75V to 5.5V or 4.5V to 5.5V)
Symbol
Parameter
M48Z2M1 / M48Z2M1Y
-70
Min
Max
tAVAV
Write Cycle Time
70
tAVWL
Address Valid to Write Enable Low
0
tAVEL
Address Valid to Chip Enable Low
0
tWLWH
Write Enable Pulse Width
55
tELEH
Chip Enable Low to Chip Enable High
55
tWHAX
Write Enable High to Address Transition
5
tEHAX
Chip Enable High to Address Transition
15
tDVWH
Input Valid to Write Enable High
30
tDVEH
Input Valid to Chip Enable High
30
tWHDX
Write Enable High to Input Transition
0
tEHDX
Chip Enable High to Input Transition
10
tWLQZ (1,2) Write Enable Low to Output Hi-Z
25
tAVWH
Address Valid to Write Enable High
65
tAVEH
Address Valid to Chip Enable High
65
tWHQX (1,2) Write Enable High to Output Transition
5
Notes: 1. CL = 5pF (see Figure 4).
2. If E goes low simultaneously with W going low, the outputs remain in the high-impedance state.
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
POWER SUPPLY DECOUPLING and UNDER-
SHOOT PROTECTION
ICC transients, including those produced by output
switching, can produce voltage fluctuations, result-
ing in spikes on the VCC bus. These transients can
be reduced if capacitors are used to store energy,
which stabilizes the VCC bus. The energy stored in
the bypass capacitors will be released as low going
spikes are generated or energy will be absorbed
when overshoots occur. A bypass capacitor value
of 0.1µF (as shown in Figure 8) is recommended
in order to provide the needed filtering.
In addition to transients that are caused by normal
SRAM operation, power cycling can generate
negative voltage spikes on VCC that drive it to
values below VSS by as much as one Volt. These
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 VCC to VSS (cathode
connected to VCC, anode to VSS). Schottky diode
1N5817 is recommended for through hole and
MBRS120T3 is recommended for surface mount.
Figure 8. Supply Voltage Protection
VCC
0.1µF
VCC
DEVICE
VSS
AI02169
8/12
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