Operating features
M93C86, M93C76, M93C66, M93C56, M93C46
3
3.1
3.1.1
Operating features
Supply voltage (V
CC
)
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. 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
).
3.1.2
Power-up conditions
When the power supply is turned on, V
CC
rises from V
SS
to V
CC
. During this time, the Chip
Select (S) line is not allowed to float and should be driven to V
SS
, it is therefore
recommended to connect the S line to V
SS
via a suitable pull-down resistor.
The V
CC
rise time must not vary faster than 1 V/µs.
3.1.3
Power-up and 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
and
When V
CC
passes the POR threshold, the device is reset and is in the following state:
●
●
Standby Power mode
deselected (assuming that there is a pull-down resistor on the S line)
3.1.4
Power-down
At power-down (continuous decrease in V
CC
), as soon as V
CC
drops from the normal
operating voltage to below the power on reset threshold voltage, the device stops
responding to any instruction sent to it.
During power-down, the device must be deselected and in the Standby Power mode (that is,
there should be no internal Write cycle in progress).
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