Symbol
Parameter
M48Z2M1 / M48Z2M1Y
Unit
-70
Min
Max
t
AVAV
Write Cycle Time
70
ns
t
AVWL
Address Valid to Write Enable Low
0
ns
t
AVEL
Address Valid to Chip Enable Low
0
ns
t
WLWH
Write Enable Pulse Width
55
ns
t
ELEH
Chip Enable Low to Chip Enable High
55
ns
t
WHAX
Write Enable High to Address Transition
5
ns
t
EHAX
Chip Enable High to Address Transition
15
ns
t
DVWH
Input Valid to Write Enable High
30
ns
t
DVEH
Input Valid to Chip Enable High
30
ns
t
WHDX
Write Enable High to Input Transition
0
ns
t
EHDX
Chip Enable High to Input Transition
10
ns
t
WLQZ
(1,2)
Write Enable Low to Output Hi-Z
25
ns
t
AVWH
Address Valid to Write Enable High
65
ns
t
AVEH
Address Valid to Chip Enable High
65
ns
t
WHQX (1,2)
Write Enable High to Output Transition
5
ns
Notes:
1. C
= 5pF (see Figure 4).
2. If E goes low simultaneously with W going low, the outputs remain in the high-impedance state.
Table 10. Write Mode AC Characteristics
(T
A
= 0 to 70
°
C; V
CC
= 4.75V to 5.5V or 4.5V to 5.5V)
POWER SUPPLY DECOUPLING and UNDER-
SHOOT PROTECTION
I
CC
transients, including those produced by output
switching, can produce voltage fluctuations, result-
ing in spikes on the V
CC
bus. These transients can
be reduced if capacitors are used to store energy,
which stabilizes the V
CC
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 0.1
μ
F (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 V
CC
that drive it to
values below V
SS
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 V
CC
to V
SS
(cathode
connected to V
CC
, anode to V
SS
). Schottky diode
1N5817 is recommended for through hole and
MBRS120T3 is recommended for surface mount.
AI02169
VCC
0.1
μ
F
DEVICE
VCC
VSS
Figure 8. Supply Voltage Protection
8/12
M48Z2M1, M48Z2M1Y