AT24C02A/04A/08A
4
Note: 1. This parameter is characterized and is not 100% tested.
Device Operation
CLOCK and DATA TRANSITIONS:
The SDA pin is nor-
mally pulled high with an external device. Data on the SDA
pin may change only during SCL low time periods (refer to
Data Validity timing diagram). Data changes during SCL
high periods will indicate a start or stop condition as
defined below.
START CONDITION:
A high-to-low transition of SDA with
SCL high is a start condition which must precede any other
command (refer to Start and Stop Definition timing dia-
gram).
STOP CONDITION:
A low-to-high transition of SDA with
SCL high is a stop condition. After a read sequence, the
stop command will place the EEPROM in a standby power
mode (refer to Start and Stop Definition timing diagram).
ACKNOWLEDGE:
All addresses and data words are seri-
ally transmitted to and from the EEPROM in 8 bit words
.
The
EEPROM sends a zero to acknowledge that it has
received each word. This happens during the ninth clock
cycle.
STANDBY MODE:
The AT24C02A/04A/08A features a low
power standby mode which is enabled: (a) upon power-up
and (b) after the receipt of the STOP bit and the completion
of any internal operations.
MEMORY RESET:
After an interruption in protocol, power
loss or system reset, any 2-wire part can be reset by follow-
ing these steps:(a) Clock up to 9 cycles, (b) look for SDA
high in each cycle while SCL is high and then (c) create a
start condition as SDA is high.
AC Characteristics
Applicable over recommended operating range from T
A
= -40
°
C to +85
°
C, V
CC
= +1.8V to +5.5V, CL = 1 TTL Gate and
100 pF (unless otherwise noted).
Symbol Parameter
2.7-, 2.5-, 1.8-volt 5.0-volt
UnitsMin Max Min Max
f
SCL
Clock Frequency, SCL 100 400 kHz
t
LOW
Clock Pulse Width Low 4.7 1.2
µ
s
t
HIGH
Clock Pulse Width High 4.0 0.6
µ
s
t
I
Noise Suppression Time
(1)
100 50 ns
t
AA
Clock Low to Data Out Valid 0.1 4.5 0.1 0.9
µ
s
t
BUF
Time the bus must be free before
a new transmission can start
(1)
4.7 1.2
µ
s
t
HD.STA
Start Hold Time 4.0 0.6
µ
s
t
SU.STA
Start Set-up Time 4.7 0.6
µ
s
t
HD.DAT
Data In Hold Time 0 0
µ
s
t
SU.DAT
Data In Set-up Time 200 100 ns
t
R
Inputs Rise Time
(1)
1.0 0.3
µ
s
t
F
Inputs Fall Time
(1)
300 300 ns
t
SU.STO
Stop Set-up Time 4.7 0.6
µ
s
t
DH
Data Out Hold Time 100 50 ns
t
WR
Write Cycle Time 10 10 ms
Endurance
(1)
5.0V, 25
°
C, Page Mode 1M 1M
Write
Cycles
