Datasheet

DocID5124 Rev 6 9/37
M93S46-W M93S56-W M93S66-W Signal description
2.7 V
SS
ground
V
SS
is the reference for the V
CC
supply voltage.
2.8 Supply voltage (V
CC
)
2.8.1 Operating supply voltage V
CC
Prior to selecting the memory and issuing instructions to it, a valid and stable VCC voltage
within the specified [V
CC
(min), V
CC
(max)] range must be applied (see Table 5: Operating
conditions (M93Sx6-W)). 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
). 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.
2.8.2 Device reset
In order to prevent inadvertent write operations during power-up, a power-on-reset (POR)
circuit is included. At power-up, the device does not respond to any instruction until V
CC
reaches the internal reset threshold voltage
When V
CC
passes over the POR threshold, the device is reset and is in the following state:
• in Standby Power mode
• deselected
The device must not be accessed until VCC reaches a valid and stable V
CC
voltage within
the specified [V
CC
(min), V
CC
(max)] range defined in Table 5: Operating conditions
(M93Sx6-W).
2.8.3 Power-up conditions
When the power supply is turned on, V
CC
must rise continuously from V
SS
to V
CC
. During
this time, the Chip Select (S) line is not allowed to float but should be driven low. It is
therefore recommended to connect the S line to V
CC
via a suitable pull-down resistor.
2.8.4 Power-down
During power-down (continuous decrease in the V
CC
supply voltage below the minimum
V
CC
operating voltage defined in Table 5: Operating conditions (M93Sx6-W), the device
must be:
• deselected (S driven low)
• in Standby Power mode (there should not be any internal write cycle in progress).