Features
•
Low-voltage and Standard-voltage Operation, VCC = 2.7V–5.5V
•
Internally Organized 128 x 8 (1K), 256 x 8 (2K), 512 x 8 (4K),
•
•
•
•
•
•
•
•
1024 x 8 (8K), or 2048 x 8 (16K)
Two-wire Serial Interface
Schmitt Trigger, Filtered Inputs for Noise Suppression
Bidirectional Data Transfer Protocol
400 kHz Compatibility
8-byte Page (1K, 2K), 16-byte Page (4K, 8K, 16K) Write Modes
Partial Page Writes Allowed
Self-timed Write Cycle (5 ms max)
High Reliability
– Endurance: One Million Write Cycles
– Data Retention: 100 Years
– ESD Protection: >3000V
Description
The AT24C01A/02SC/04SC/08SC/16SC provide 1024/2048/4096/8192/16384 bits of
serial, electrically-erasable, and programmable read-only memory (EEPROM) orga-
nized as 128/256/512/1024/2048 words of 8 bits each. The devices are optimized for
use in smart card applications where low-power and low-voltage operation may be
essential. The devices are available in several standard ISO 7816 smart card modules
(see
Ordering Information,
pages 12–13). All devices are functionally equivalent to
Atmel serial EEPROM products offered in standard IC packages (PDIP, SOIC, TSSOP,
MAP), with the exception of the slave address and write protect functions, which are
not required for smart card applications.
Table 1.
Pin Configuration
Pad Name
VCC
GND
SCL
SDA
NC
Description
Power Supply Voltage
Ground
Serial Clock Input
Serial Data Input/Output
No Connect
ISO Module Contact
C1
C5
C3
C7
C2, C4, C6, C8
Two-wire Serial
EEPROM Smart
Card Modules
1K (128 x 8)
2K (256 x 8)
4K (512 x 8)
8K (1024 x 8)
16K (2048 x 8)
AT24C01ASC
AT24C02SC
AT24C04SC
AT24C08SC
AT24C16SC
Figure 1.
Card Module Contact
VCC
NC
1610B–SEEPR–04/04
1
Absolute Maximum Ratings
Operating Temperature......................................−55°C to +125°C
Storage Temperature
.........................................−65°C
to +150°C
Voltage on Any Pin
with Respect to Ground
........................................ −1.0V
to +7.0V
Maximum Operating Voltage .......................................... 6.25V
DC Output Current........................................................ 5.0 mA
*NOTICE:
Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent dam-
age to the device. This is a stress rating only and
functional operation of the device at these or any
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect device
reliability.
Figure 2.
Block Diagram
Pin Description
SERIAL CLOCK (SCL):
The SCL input is used to positive edge clock data into each
EEPROM device and negative edge clock data out of each device.
SERIAL DATA (SDA):
The SDA pin is bidirectional for serial data transfer. This pin is
open-drain driven and may be wire-ORed with any number of other open-drain or open-
collector devices.
Memory Organization
AT24C01ASC, 1K SERIAL EEPROM:
Internally organized with 16 pages of 8 bytes
each, the 1K requires a 7-bit data word address for random word addressing.
AT24C02SC, 2K SERIAL EEPROM:
Internally organized with 32 pages of 8 bytes
each, the 2K requires an 8-bit data word address for random word addressing.
2
AT24C01ASC/02SC/04SC/08SC/16SC
1610B–SEEPR–04/04
AT24C01ASC/02SC/04SC/08SC/16SC
AT24C04SC, 4K SERIAL EEPROM:
Internally organized with 32 pages of 16 bytes
each, the 4K requires a 9-bit data word address for random word addressing.
AT24C08SC, 8K SERIAL EEPROM:
Internally organized with 64 pages of 16 bytes
each, the 8K requires a 10-bit data word address random word addressing.
AT24C16SC, 16K SERIAL EEPROM:
Internally organized with 128 pages of 16 bytes
each, the 16K requires an 11-bit data word address random word addressing.
Pin Capacitance
Table 2.
Pin Capacitance
(1)
Applicable over recommended operating range from T
A
= 25°C, f = 1.0 MHz, V
CC
= +2.7V
Symbol
C
I/O
C
IN
Note:
Test Condition
Input/Output Capacitance (SDA)
Input Capacitance (SCL)
1. This parameter is characterized and is not 100% tested.
Max
8
6
Units
pF
pF
Conditions
V
I/O
= 0V
V
IN
= 0V
DC Characteristics
Table 3.
DC Characteristics
(1)
Symbol
V
CC
I
CC
I
CC
I
SB1
I
SB2
I
LI
I
LO
V
IL
V
IH
V
OL
Notes:
Parameter
Supply Voltage
Supply Current V
CC
= 5.0V
Supply Current V
CC
= 5.0V
Standby Current V
CC
= 2.7V
Standby Current V
CC
= 5.0V
Input Leakage Current
Output Leakage Current
Input Low Level
(
2)
Input High Level
(
2)
Output Low Level V
CC
= 3.0V
I
OL
= 2.1 mA
READ at 100 kHz
WRITE at 100 kHz
V
IN
= V
CC
or GND
V
IN
= V
CC
or GND
V
IN
= V
CC
or GND
V
OUT
= V
CC
or GND
−0.6
V
CC
x 0.7
Test Condition
Min
2.7
0.4
2.0
1.6
8.0
0.10
0.05
Typ
Max
5.5
1.0
3.0
4.0
18.0
3.0
3.0
V
CC
x 0.3
V
CC
+ 0.5
0.4
Units
V
mA
mA
µA
µA
µA
µA
V
V
V
1. Applicable over recommended operating range from: T
AC
= 0°C to +70°C, V
CC
= +2.7V to +5.5V (unless otherwise noted)
2. V
IL
min and V
IH
max are reference only and are not tested.
AC Characteristics
Table 4.
AC Characteristics
(1)
Symbol
f
SCL
t
LOW
t
HIGH
t
I
t
AA
t
BUF
Parameter
Clock Frequency, SCL
Clock Pulse Width Low
Clock Pulse Width High
Noise Suppression Time
(
2)
Clock Low to Data Out Valid
Time the bus must be free before a new transmission can start
(
1)
0.1
1.2
1.2
0.6
50
0.9
Min
Max
400
Units
kHz
µs
µs
ns
µs
µs
3
1610B–SEEPR–04/04
Table 4.
AC Characteristics
(1)
(Continued)
Symbol
t
HD.STA
t
SU.STA
t
HD.DAT
t
SU.DAT
t
R
t
F
t
SU.STO
t
DH
t
WR
Endurance
(
1)
Note:
Parameter
Start Hold Time
Start Setup Time
Data In Hold Time
Data In Setup Time
Inputs Rise Time
(
2)
Inputs Fall Time
(
2)
Stop Setup Time
Data Out Hold Time
Write Cycle Time
5.0V, 25°C, Byte Mode
1M
0.6
50
5
Min
0.6
0.6
0
100
0.3
300
Max
Units
µs
µs
µs
ns
µs
ns
µs
ns
ms
Write Cycles
1. Applicable over recommended operating range from T
A
= 0°C to +70°C, V
CC
= +2.7V to +5.5V, CL = 1 TTL Gate and 100 pF
(unless otherwise noted)
2. This parameter is characterized and is not 100% tested.
Device Operation
CLOCK AND DATA TRANSITIONS:
The SDA pin is normally pulled high with an exter-
nal device. Data on the SDA pin may change only during SCL-low time periods (see
Figure 3 on page 5). 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
that must precede any other command (see Figure 4 on page 6).
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 (see Figure 4 on page 6).
ACKNOWLEDGE:
All addresses and data words are serially transmitted to and from the
EEPROM in 8-bit words. Each word requires the receiver to acknowledge that it has
received a valid command or data byte. During the transmission of commands from the
host to the EEPROM, the EEPROM will send a zero to the host to acknowledge that it
has received a valid command byte. This occurs on the ninth clock cycle of the com-
mand byte. During read operations, the host will send a zero to the EEPROM to
acknowledge that it has received a valid data byte and that it requests the next sequen-
tial data byte to be transmitted during the subsequent eight clock cycles. This occurs on
the ninth clock cycle of the data byte. If the host does not transmit this acknowledge bit,
the EEPROM will disable the read operation and return to standby mode.
STANDBY MODE:
The AT24C01ASC/02SC/04SC/08SC/16SC feature a low-power
standby mode that is enabled upon power-up and 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
two-wire part can be reset by following these steps:
1. Clock up to 9 cycles.
2. Look for SDA high in each cycle while SCL is high.
3. Create a start condition as SDA is high.
4
AT24C01ASC/02SC/04SC/08SC/16SC
1610B–SEEPR–04/04
AT24C01ASC/02SC/04SC/08SC/16SC
Timing Diagrams
Bus Timing
Figure 1.
Bus Timing
Note:
SCL: Serial Clock, SDA: Serial Data I/O
Write Cycle Timing
Figure 2.
Write Cycle Timing
t
WR(1)
Notes:
1. The write cycle time t
WR
is the time from a valid stop condition of a write sequence to
the end of the internal clear/write cycle.
2. SCL: Serial Clock, SDA: Serial Data I/O
Data Validity
Figure 3.
Data Validity
SDA
SCL
DATA STABLE
DATA STABLE
DATA
CHANGE
5
1610B–SEEPR–04/04
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