M34D64-W Signal description
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2.5 V
SS
ground
V
SS
is the reference for the V
CC
supply voltage.
2.6 Supply voltage (V
CC
)
2.6.1 Operating supply voltage V
CC
Prior to selecting the memory and issuing instructions to it, a valid and stable V
CC
voltage
within the specified [V
CC
(min), V
CC
(max)] range must be applied (see Ta bl e 7 ). In order to
secure a stable DC supply voltage, it is recommended to decouple the V
CC
line with a
suitable capacitor (usually of the order of 10 nF to 100 nF) close to the V
CC
/V
SS
package
pins.
This voltage must remain stable and valid until the end of the transmission of the instruction
and, for a Write instruction, until the completion of the internal write cycle (t
W
).
2.6.2 Power-up conditions
When the power supply is turned on, V
CC
rises from V
SS
to V
CC
, the V
CC
rise time must not
vary faster than 1 V/µs.
2.6.3 Device reset
In order to prevent inadvertent write operations during power-up, a power-on-reset (POR)
circuit is included. At power-up (continuous rise of V
CC
), the device does not respond to any
instruction until V
CC
has reached the power-on-reset threshold voltage (this threshold is
lower than the minimum V
CC
operating voltage defined in Ta bl e 7). When V
CC
passes over
the POR threshold, the device is reset and enters the Standby Power mode. It must not be
accessed until V
CC
reaches a valid and stable V
CC
voltage within the specified [V
CC
(min),
V
CC
(max)] range.
In a similar way, during power-down (continuous decrease in V
CC
), as soon as V
CC
drops
below the power-on-reset threshold voltage, the device stops responding to any instruction
sent to it.
2.6.4 Power-down conditions
During power-down (continuous decrease in V
CC
), the device must be in Standby Power
mode (mode reached after decoding a Stop condition, assuming that there is no internal
Write cycle in progress).
