Operating features
M93C86, M93C76, M93C66, M93C56, M93C46
3
Operating features
3.1
Supply voltage (VCC)
3.1.1
Operating supply voltage V
CC
Prior to selecting the memory and issuing instructions to it, a valid and stable V voltage
CC
within the specified [V (min), V (max)] range must be applied. In order to secure a stable
CC
CC
DC supply voltage, it is recommended to decouple the V line with a suitable capacitor
CC
(usually of the order of 10 nF to 100 nF) close to the V /V package pins.
CC SS
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
3.1.3
Power-up conditions
When the power supply is turned on, V rises from V to V . During this time, the Chip
Select (S) line is not allowed to float and should be driven to V , it is therefore
recommended to connect the S line to V via a suitable pull-down resistor.
CC
SS
CC
SS
CC
The V rise time must not vary faster than 1 V/µs.
CC
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 ), the device does not respond to any
CC
instruction until V has reached the power on reset threshold voltage (this threshold is
CC
lower than the minimum V operating voltage defined in Table 9, Table 10 and Table 11).
CC
When V passes the POR threshold, the device is reset and is in the following state:
CC
●
●
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 ), as soon as V drops from the normal
CC
CC
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).
10/38
STMICROELECTRONICS [ ST ]
