M24128, M24C64, M24C32
Signal description
2.5
V
SS
ground
V
SS
is the reference for the V
CC
supply voltage.
2.6
2.6.1
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 (see
and
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
Internal 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
has passed the POR threshold, the device is reset and is in Standby Power
mode.
2.6.3
Power-down
At power-down (continuous decrease of 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).
Figure 4.
20
Maximum RP value (kΩ)
16
R
P
12
8
4
0
10
100
C (pF)
AI01665b
Maximum R
P
value versus bus parasitic capacitance (C) for an I
2
C bus
VCC
R
P
SDA
MASTER
fc = 100kHz
fc = 400kHz
SCL
C
C
1000
9/35
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