24AA64/24LC64/24FC64
64K I2C™ Serial EEPROM
Device Selection Table
Part
Number
VCC
Range
Max. Clock
Frequency
Temp.
Ranges
24AA64
1.7-5.5
400 kHz(1)
I, E
24LC64
2.5-5.5
400 kHz
I, E
1.7-5.5
(2)
24FC64
Note 1:
2:
1 MHz
• Pb-Free and RoHS Compliant
• Temperature Ranges:
- Industrial (I): -40°C to +85°C
- Automotive (E): -40°C to +125°C
Description:
The Microchip Technology Inc. 24AA64/24LC64/
24FC64 (24XX64*) is a 64 Kbit Electrically Erasable
PROM. The device is organized as a single block of
8K x 8-bit memory with a 2-wire serial interface. Lowvoltage design permits operation down to 1.7V, with
standby and active currents of only 1 A and 3 mA,
respectively. It has been developed for advanced, lowpower applications such as personal communications
or data acquisition. The 24XX64 also has a page write
capability for up to 32 bytes of data. Functional
address lines allow up to eight devices on the same
bus, for up to 512 Kbits address space. The 24XX64 is
available in the standard 8-pin PDIP, surface mount
SOIC, SOIJ, TSSOP, DFN, TDFN and MSOP
packages. The 24XX64 is also available in the 5-lead
SOT-23, and Chip Scale packages.
I
200 Years
• Factory Programming Available
• Packages include 8-lead PDIP, SOIC, SOIJ,
TSSOP, X-Rotated TSSOP, MSOP, DFN, TDFN,
5-lead SOT-23 or Chip Scale
Block Diagram
HV
Generator
A0 A1 A2 WP
I/O
Control
Logic
Memory
Control
Logic
EEPROM
Array
XDEC
Page
Latches
I/O
SCL
YDEC
SDA
VCC
VSS
Sense Amp.
R/W Control
Package Types
PDIP/MSOP/SOIC/SOIJ/TSSOP
A0
1
8
VCC
A1
2
7
WP
A2
3
6
SCL
VSS
4
5
SDA
Note
1:
DFN/TDFN
SOT-23
X-Rotated TSSOP
(X/ST)
WP
VCC
A0
A1
1
2
3
4
Available in I-temp, “AA” only.
8
7
6
5
SCL
VSS
SCL
SDA
VSS SDA
A2
1
5
A0 1
A1 2
2
3
WP
4
A2 3
VCC VSS 4
8 VCC
7 WP
6 SCL
5 SDA
CS (Chip Scale)(1)
VCC
1
WP
SCL
2
VSS
5
SDA
3
4
(Top Down View,
Balls Not Visible)
* 24XX64 is used in this document as a generic part number for the 24AA64/24LC64/24FC64 devices.
1997-2012 Microchip Technology Inc.
DS21189T-page 1
24AA64/24LC64/24FC64
1.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings (†)
VCC .............................................................................................................................................................................6.5V
All inputs and outputs w.r.t. VSS ......................................................................................................... -0.3V to VCC +1.0V
Storage temperature ...............................................................................................................................-65°C to +150°C
Ambient temperature with power applied ................................................................................................-40°C to +125°C
ESD protection on all pins 4 kV
† NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. This is a stress rating only and functional operation of the device at those or any other conditions above those
indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for
extended periods may affect device reliability.
TABLE 1-1:
DC CHARACTERISTICS
DC CHARACTERISTICS
Param.
No.
Sym.
Characteristic
Industrial (I):
TA = -40°C to +85°C, VCC = +1.7V to +5.5V
Automotive (E): TA = -40°C to +125°C, VCC = +1.7V to +5.5V
Min.
Typ.
Max.
Units
Conditions
—
—
—
—
—
—
A0, A1, A2, WP, SCL
and SDA pins
D1
VIH
High-level input voltage
0.7 VCC
—
—
V
—
D2
VIL
Low-level input voltage
—
—
0.3 VCC
0.2 VCC
V
V
VCC 2.5V
VCC 2.5V
D3
VHYS
Hysteresis of Schmitt
Trigger inputs (SDA,
SCL pins)
0.05 VCC
—
—
V
VCC 2.5V (Note 1)
D4
VOL
Low-level output voltage
—
—
0.40
V
IOL = 3.0 mA @ VCC = 4.5V
IOL = 2.1 mA @ VCC = 2.5V
D5
ILI
Input leakage current
—
—
±1
A
VIN = VSS or VCC, WP = VSS
VIN = VSS or VCC, WP = VCC
D6
ILO
Output leakage current
—
—
±1
A
VOUT = VSS or VCC
D7
CIN,
COUT
Pin capacitance
(all inputs/outputs)
—
—
10
pF
VCC = 5.0V (Note 1)
TA = 25°C, FCLK = 1 MHz
D8
ICC write Operating current
—
0.1
3
mA
VCC = 5.5V, SCL = 400 kHz
—
0.05
400
A
—
—
0.01
—
1
5
A
A
D9
ICC read
D10
ICCS
Note 1:
2:
Standby current
Industrial
Automotive
SDA = SCL = VCC
A0, A1, A2, WP = VSS
This parameter is periodically sampled and not 100% tested.
Typical measurements taken at room temperature.
DS21189T-page 2
1997-2012 Microchip Technology Inc.
24AA64/24LC64/24FC64
TABLE 1-2:
AC CHARACTERISTICS
Electrical Characteristics:
Industrial (I):
VCC = +1.7V to 5.5V TA = -40°C to +85°C
Automotive (E): VCC = +1.7V to 5.5V TA = -40°C to 125°C
AC CHARACTERISTICS
Param.
No.
Sym.
Characteristic
Min.
Max.
Units
Conditions
1
FCLK
Clock frequency
—
—
—
—
100
400
400
1000
kHz
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 2.5V 24FC64
2.5V VCC 5.5V 24FC64
2
THIGH
Clock high time
4000
600
600
500
—
—
—
—
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 2.5V 24FC64
2.5V VCC 5.5V 24FC64
3
TLOW
Clock low time
4700
1300
1300
500
—
—
—
—
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 2.5V 24FC64
2.5V VCC 5.5V 24FC64
4
TR
SDA and SCL rise time
(Note 1)
—
—
—
1000
300
300
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 5.5V 24FC64
5
TF
SDA and SCL fall time
(Note 1)
—
—
300
100
ns
All except, 24FC64
1.7V VCC 5.5V 24FC64
6
THD:STA Start condition hold time
4000
600
600
250
—
—
—
—
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 2.5V 24FC64
2.5V VCC 5.5V 24FC64
7
TSU:STA
4700
600
600
250
—
—
—
—
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 2.5V 24FC64
2.5V VCC 5.5V 24FC64
Start condition setup time
8
THD:DAT Data input hold time
0
—
ns
(Note 2)
9
TSU:DAT Data input setup time
250
100
100
—
—
—
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 5.5V 24FC64
10
TSU:STO Stop condition setup time
4000
600
600
250
—
—
—
—
ns
1.7 V VCC 2.5V
2.5 V VCC 5.5V
1.7V VCC 2.5V 24FC64
2.5 V VCC 5.5V 24FC64
11
TSU:WP
WP setup time
4000
600
600
—
—
—
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 5.5V 24FC64
12
THD:WP
WP hold time
4700
1300
1300
—
—
—
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 5.5V 24FC64
Note 1: Not 100% tested. CB = total capacitance of one bus line in pF.
2: As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region
(minimum 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions.
3: The combined TSP and VHYS specifications are due to new Schmitt Trigger inputs, which provide improved
noise spike suppression. This eliminates the need for a TI specification for standard operation.
4: This parameter is not tested but ensured by characterization. For endurance estimates in a specific
application, please consult the Total Endurance™ Model, which can be obtained from Microchip’s web site
at www.microchip.com.
1997-2012 Microchip Technology Inc.
DS21189T-page 3
24AA64/24LC64/24FC64
Electrical Characteristics:
Industrial (I):
VCC = +1.7V to 5.5V TA = -40°C to +85°C
Automotive (E): VCC = +1.7V to 5.5V TA = -40°C to 125°C
AC CHARACTERISTICS
Param.
No.
Sym.
Characteristic
Min.
Max.
Units
Conditions
—
—
—
—
3500
900
900
400
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 2.5V 24FC64
2.5V VCC 5.5V 24FC64
4700
1300
1300
500
—
—
—
—
ns
1.7V VCC 2.5V
2.5V VCC 5.5V
1.7V VCC 2.5V 24FC64
2.5V VCC 5.5V 24FC64
10 + 0.1CB
250
250
ns
All except, 24FC64 (Note 1)
24FC64 (Note 1)
13
TAA
Output valid from clock
(Note 2)
14
TBUF
Bus free time: Time the bus
must be free before a new
transmission can start
15
TOF
Output fall time from VIH
minimum to VIL maximum
CB 100 pF
16
TSP
Input filter spike suppression
(SDA and SCL pins)
—
50
ns
All except, 24FC64 (Notes 1
and 3)
17
TWC
Write cycle time (byte or
page)
—
5
ms
—
1,000,000
—
18
—
Endurance
cycles Page Mode 25°C, 5.5V (Note 4)
Note 1: Not 100% tested. CB = total capacitance of one bus line in pF.
2: As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region
(minimum 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions.
3: The combined TSP and VHYS specifications are due to new Schmitt Trigger inputs, which provide improved
noise spike suppression. This eliminates the need for a TI specification for standard operation.
4: This parameter is not tested but ensured by characterization. For endurance estimates in a specific
application, please consult the Total Endurance™ Model, which can be obtained from Microchip’s web site
at www.microchip.com.
FIGURE 1-1:
BUS TIMING DATA
5
SCL
SDA
IN
7
3
4
D3
2
8
10
9
6
16
14
13
SDA
OUT
WP
DS21189T-page 4
(protected)
(unprotected)
11
12
1997-2012 Microchip Technology Inc.
24AA64/24LC64/24FC64
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
PIN FUNCTION TABLE
Name PDIP SOIC TSSOP
Rotated
DFN(1) TDFN(1) MSOP
TSSOP
SOT-23
CS
Description
A0
1
1
1
3
1
1
1
—
—
Chip Address Input
A1
2
2
2
4
2
2
2
—
—
Chip Address Input
A2
3
3
3
5
3
3
3
—
—
Chip Address Input
VSS
4
4
4
6
4
4
4
2
2
Ground
SDA
5
5
5
7
5
5
5
3
5
Serial Address/Data I/O
SCL
6
6
6
8
6
6
6
1
4
Serial Clock
WP
7
7
7
1
7
7
7
5
3
Write-Protect Input
VCC
8
8
8
2
8
8
8
4
1
+1.7V to 5.5V Power Supply
Note 1: The exposed pad on the DFN/TDFN packages can be connected to VSS or left floating.
2.1
A0, A1, A2 Chip Address Inputs
The A0, A1 and A2 inputs are used by the 24XX64 for
multiple device operation. The levels on these inputs
are compared with the corresponding bits in the slave
address. The chip is selected if the compare is true.
Up to eight devices may be connected to the same bus
by using different Chip Select bit combinations. These
inputs must be connected to either VCC or VSS.
In most applications, the chip address inputs A0, A1
and A2 are hard-wired to logic ‘0’ or logic ‘1’. For
applications in which these pins are controlled by a
microcontroller or other programmable device, the chip
address pins must be driven to logic ‘0’ or logic ‘1’
before normal device operation can proceed. Address
pins are not available in the SOT-23 or Chip Scale
packages.
2.2
Serial Data (SDA)
SDA is a bidirectional pin used to transfer addresses
and data into and out of the device. Since it is an opendrain terminal, the SDA bus requires a pull-up resistor
to VCC (typical 10 k for 100 kHz, 2 kfor 400 kHz).
2.3
Serial Clock (SCL)
The SCL input is used to synchronize the data transfer
from and to the device.
2.4
Write-Protect (WP)
This pin must be connected to either VSS or VCC. If tied
to VSS, write operations are enabled. If tied to VCC,
write operations are inhibited but read operations are
not affected.
3.0
FUNCTIONAL DESCRIPTION
The 24XX64 supports a bidirectional, 2-wire bus and
data transmission protocol. A device that sends data
onto the bus is defined as transmitter, while a device
receiving data is defined as a receiver. The bus has to
be controlled by a master device which generates the
Serial Clock (SCL), controls the bus access and
generates the Start and Stop conditions, while the
24XX64 works as slave. Both master and slave can
operate as transmitter or receiver, but the master
device determines which mode is activated.
For normal data transfer, SDA is allowed to change
only during SCL low. Changes during SCL high are
reserved for indicating the Start and Stop conditions.
1997-2012 Microchip Technology Inc.
DS21189T-page 5
24AA64/24LC64/24FC64
4.0
BUS CHARACTERISTICS
The following bus protocol has been defined:
• Data transfer may be initiated only when the bus
is not busy
• During data transfer, the data line must remain
stable whenever the clock line is high. Changes in
the data line while the clock line is high will be
interpreted as a Start or Stop condition
The data on the line must be changed during the low
period of the clock signal. There is one clock pulse per
bit of data.
Accordingly, the following bus conditions have been
defined (Figure 4-1).
Each data transfer is initiated with a Start condition and
terminated with a Stop condition. The number of data
bytes transferred between Start and Stop conditions is
determined by the master device and is, theoretically,
unlimited (although only the last thirty two will be stored
when doing a write operation). When an overwrite does
occur, it will replace data in a first-in first-out (FIFO)
fashion.
4.1
4.5
Bus Not Busy (A)
Each receiving device, when addressed, is obliged to
generate an acknowledge after the reception of each
byte. The master device must generate an extra clock
pulse which is associated with this Acknowledge bit.
Both data and clock lines remain high.
4.2
Start Data Transfer (B)
A high-to-low transition of the SDA line while the clock
(SCL) is high determines a Start condition. All
commands must be preceded by a Start condition.
4.3
Stop Data Transfer (C)
A low-to-high transition of the SDA line while the clock
(SCL) is high determines a Stop condition. All
operations must be ended with a Stop condition.
4.4
Data Valid (D)
The state of the data line represents valid data when,
after a Start condition, the data line is stable for the
duration of the high period of the clock signal.
FIGURE 4-1:
(A)
Acknowledge
Note:
The 24XX64 does not generate any
Acknowledge bits
if an internal
programming cycle is in progress.
The device that acknowledges has to pull down the
SDA line during the Acknowledge clock pulse in such a
way that the SDA line is stable low during the high
period of the acknowledge related clock pulse. Of
course, setup and hold times must be taken into
account. During reads, a master must signal an end of
data to the slave by not generating an Acknowledge bit
on the last byte that has been clocked out of the slave.
In this case, the slave (24XX64) will leave the data line
high to enable the master to generate the Stop
condition.
DATA TRANSFER SEQUENCE ON THE SERIAL BUS
(B)
(D)
Start
Condition
Address or
Acknowledge
Valid
(D)
(C)
(A)
SCL
SDA
DS21189T-page 6
Data
Allowed
to Change
Stop
Condition
1997-2012 Microchip Technology Inc.
24AA64/24LC64/24FC64
5.0
DEVICE ADDRESSING
A control byte is the first byte received following the
Start condition from the master device (Figure 5-1).
The control byte consists of a four-bit control code. For
the 24XX64, this is set as ‘1010’ binary for read and
write operations. The next three bits of the control byte
are the Chip Select bits (A2, A1, A0). The Chip Select
bits allow the use of up to eight 24XX64 devices on the
same bus and are used to select which device is
accessed. The Chip Select bits in the control byte must
correspond to the logic levels on the corresponding A2,
A1 and A0 pins for the device to respond. These bits
are, in effect, the three Most Significant bits of the word
address.
For the SOT-23 and Chip Scale packages, the address
pins are not available. During device addressing, the
A2, A1 and A0 Chip Select bits (Figure 5-2) should be
set to ‘0’.
The last bit of the control byte defines the operation to
be performed. When set to a ‘1’, a read operation is
selected. When set to a ‘0’, a write operation is
selected. The next two bytes received define the
address of the first data byte (Figure 5-2). Because
only A12...A0 are used, the upper-three address bits
are “don’t care” bits. The upper-address bits are
transferred first, followed by the Less Significant bits.
Following the Start condition, the 24XX64 monitors the
SDA bus, checking the device-type identifier being
transmitted. Upon receiving a ‘1010’ code and appropriate device-select bits, the slave device outputs an
FIGURE 5-2:
0
FIGURE 5-1:
CONTROL BYTE FORMAT
Read/Write Bit
Chip Select
Bits
Control Code
S
1
0
1
0
A2
A1
A0 R/W ACK
Slave Address
Start Bit
5.1
Acknowledge Bit
Contiguous Addressing Across
Multiple Devices
The Chip Select bits A2, A1 and A0 can be used to
expand the contiguous address space for up to 512K
bits by adding up to eight 24XX64 devices on the same
bus. In this case, software can use A0 of the control
byte as address bit A13; A1 as address bit A14; and A2
as address bit A15. It is not possible to sequentially
read across device boundaries.
The SOT-23 and Chip Scale packages do not support
multiple device addressing on the same bus.
ADDRESS SEQUENCE BIT ASSIGNMENTS
Control Byte
1
Acknowledge signal on the SDA line. Depending on the
state of the R/W bit, the 24XX64 will select a read or
write operation.
1
Control
Code
0
A
2
A
1
Address High Byte
A
0 R/W
Chip
Select
bits
1997-2012 Microchip Technology Inc.
x
x
x
A A A
12 11 10
Address Low Byte
A
9
A
8
A
7
•
•
•
•
•
•
A
0
x = “don’t care” bit
DS21189T-page 7
24AA64/24LC64/24FC64
6.0
WRITE OPERATIONS
6.1
Byte Write
Following the Start condition from the master, the
control code (four bits), the Chip Select (three bits) and
the R/W bit (which is a logic low) are clocked onto the
bus by the master transmitter. This indicates to the
addressed slave receiver that the address high byte will
follow once it has generated an Acknowledge bit during
the ninth clock cycle. Therefore, the next byte transmitted by the master is the high-order byte of the word
address and will be written into the Address Pointer of
the 24XX64. The next byte is the Least Significant
Address Byte. After receiving another Acknowledge
signal from the 24XX64, the master device will transmit
the data word to be written into the addressed memory
location. The 24XX64 acknowledges again and the
master generates a Stop condition. This initiates the
internal write cycle and, during this time, the 24XX64
will not generate Acknowledge signals (Figure 6-1). If
an attempt is made to write to the array with the WP pin
held high, the device will acknowledge the command,
but no write cycle will occur, no data will be written and
the device will immediately accept a new command.
After a byte Write command, the internal address counter will point to the address location following the one
that was just written.
Note:
6.2
Page Write
The write control byte, word address and the first data
byte are transmitted to the 24XX64 in the same way as
in a byte write. However, instead of generating a Stop
condition, the master transmits up to 31 additional
bytes which are temporarily stored in the on-chip page
buffer and will be written into memory once the master
has transmitted a Stop condition. Upon receipt of each
word, the five lower Address Pointer bits are internally
incremented by one. If the master should transmit more
than 32 bytes prior to generating the Stop condition, the
address counter will roll over and the previously
received data will be overwritten. As with the byte write
operation, once the Stop condition is received, an internal write cycle will begin (Figure 6-2). If an attempt is
made to write to the array with the WP pin held high, the
device will acknowledge the command, but no write
cycle will occur, no data will be written, and the device
will immediately accept a new command.
Note:
When doing a write of less than 32 bytes
the data in the rest of the page is
refreshed along with the data bytes being
written. This will force the entire page to
endure a write cycle, for this reason
endurance is specified per page.
6.3
Page write operations are limited to writing bytes within a single physical page,
regardless of the number of bytes
actually being written. Physical page
boundaries start at addresses that are
integer multiples of the page buffer size
(or ‘page size’) and end at addresses that
are integer multiples of [page size – 1]. If
a Page Write command attempts to write
across a physical page boundary, the
result is that the data wraps around to the
beginning of the current page (overwriting
data previously stored there), instead of
being written to the next page, as might be
expected. It is therefore necessary for the
application software to prevent page write
operations that would attempt to cross a
page boundary.
Write Protection
The WP pin allows the user to write-protect the entire
array (0000-1FFF) when the pin is tied to VCC. If tied to
VSS the write protection is disabled. The WP pin is
sampled at the Stop bit for every Write command
(Figure 4-1). Toggling the WP pin after the Stop bit will
have no effect on the execution of the write cycle.
DS21189T-page 8
1997-2012 Microchip Technology Inc.
24AA64/24LC64/24FC64
FIGURE 6-1:
BYTE WRITE
S
T
A
R
T
Bus Activity
Master
Control
Byte
Address
High Byte
AA
S1 01 0A
2 10 0
SDA Line
S
T
O
P
Data
xxx
P
A
C
K
Bus Activity
Address
Low Byte
A
C
K
A
C
K
A
C
K
x = “don’t care” bit
FIGURE 6-2:
PAGE WRITE
Bus Activity
Master
S
T
A
R
T
SDA Line
AA
S 10 10A
2 1 0 0
Control
Byte
Bus Activity
Address
High Byte
Address
Low Byte
Data Byte 0
S
T
O
P
Data Byte 31
P
xxx
A
C
K
A
C
K
A
C
K
A
C
K
A
C
K
x = “don’t care” bit
1997-2012 Microchip Technology Inc.
DS21189T-page 9
24AA64/24LC64/24FC64
7.0
ACKNOWLEDGE POLLING
Since the device will not acknowledge during a write
cycle, this can be used to determine when the cycle is
complete (this feature can be used to maximize bus
throughput). Once the Stop condition for a Write
command has been issued from the master, the device
initiates the internally-timed write cycle and ACK polling
can then be initiated immediately. This involves the
master sending a Start condition followed by the control
byte for a Write command (R/W = 0). If the device is still
busy with the write cycle, then no ACK will be returned.
If no ACK is returned, the Start bit and control byte must
be re-sent. If the cycle is complete, the device will
return the ACK and the master can then proceed with
the next Read or Write command. See Figure 7-1 for a
flow diagram of this operation.
FIGURE 7-1:
ACKNOWLEDGE POLLING
FLOW
Send
Write Command
Send Stop
Condition to
Initiate Write Cycle
Send Start
Send Control Byte
with R/W = 0
Did Device
Acknowledge
(ACK = 0)?
No
Yes
Next
Operation
DS21189T-page 10
1997-2012 Microchip Technology Inc.
24AA64/24LC64/24FC64
8.0
READ OPERATION
Read operations are initiated in the same way as write
operations, with the exception that the R/W bit of the
control byte is set to one. There are three basic types
of read operations: current address read, random read
and sequential read.
8.1
Current Address Read
The 24XX64 contains an address counter that maintains the address of the last word accessed, internally
incremented by one. Therefore, if the previous read
access was to address ‘n’ (n is any legal address), the
next current address read operation would access data
from address n + 1.
Upon receipt of the control byte with R/W bit set to one,
the 24XX64 issues an acknowledge and transmits the
eight-bit data word. The master will not acknowledge
the transfer, but does generate a Stop condition and the
24XX64 discontinues transmission (Figure 8-1).
8.2
Random Read
Random read operations allow the master to access
any memory location in a random manner. To
perform this type of read operation, the word address
must first be set. This is accomplished by sending
the word address to the 24XX64 as part of a write
operation (R/W bit set to ‘0’). Once the word address
is sent, the master generates a Start condition
following the acknowledge.
FIGURE 8-1:
This terminates the write operation, but not before
the internal Address Pointer is set. The master then
issues the control byte again, but with the R/W bit set
to a one. The 24XX64 will then issue an acknowledge and transmit the 8-bit data word. The master
will not acknowledge the transfer, but does generate
a Stop condition, which causes the 24XX64 to
discontinue transmission (Figure 8-2). After a
random Read command, the internal address counter will point to the address location following the one
that was just read.
8.3
Sequential Read
Sequential reads are initiated in the same way as
random reads, except that once the 24XX64 transmits
the first data byte, the master issues an acknowledge as
opposed to the Stop condition used in a random read.
This acknowledge directs the 24XX64 to transmit the
next sequentially-addressed 8-bit word (Figure 8-3).
Following the final byte being transmitted to the master,
the master will NOT generate an acknowledge, but will
generate a Stop condition. To provide sequential reads,
the 24XX64 contains an internal Address Pointer which
is incremented by one at the completion of each
operation. This Address Pointer allows the entire
memory contents to be serially read during one operation. The internal Address Pointer will automatically roll
over from address 1FFF to address 0000 if the master
acknowledges the byte received from the array address
1FFF.
CURRENT ADDRESS READ
Bus Activity
Master
S
T
A
R
T
SDA Line
S
Bus Activity
1997-2012 Microchip Technology Inc.
Control
Byte
S
T
O
P
Data (n)
P
A
C
K
N
O
A
C
K
DS21189T-page 11
24AA64/24LC64/24FC64
FIGURE 8-2:
Bus Activity
Master
SDA Line
RANDOM READ
S
T
A
R
T
Control
Byte
Address
High Byte
S1 01 0AAA0
2 1 0
xxx
A
C
K
A
C
K
Bus Activity
S
T
A
R
T
Address
Low Byte
A
C
K
Control
Byte
S 1 0 1 0 A AA1
2 10
S
T
O
P
Data
Byte
P
N
O
A
C
K
A
C
K
x = “don’t care” bit
FIGURE 8-3:
Bus Activity
Master
SEQUENTIAL READ
Control
Byte
Data n
Data n + 1
Data n + 2
S
T
O
P
Data n + x
P
SDA Line
Bus Activity
DS21189T-page 12
A
C
K
A
C
K
A
C
K
A
C
K
N
O
A
C
K
1997-2012 Microchip Technology Inc.
24AA64/24LC64/24FC64
9.0
PACKAGING INFORMATION
9.1
Package Marking Information
8-Lead PDIP (300 mil)
XXXXXXXX
T/XXXNNN
YYWW
8-Lead SOIC (3.90 mm)
Example:
24LC64
I/P e3 13F
0527
Example:
24LC64I
SN e3 0527
13F
XXXXXXXT
XXXXYYWW
NNN
8-Lead SOIC (5.28 mm)
Example:
24LC64
I/SM e3
052713F
XXXXXXXX
T/XXXXXX
YYWWNNN
8-Lead TSSOP
Example:
XXXX
4LB
TYWW
I527
NNN
13F
8-Lead MSOP
Example:
XXXXXT
4L64I
YWWNNN
52713F
8-Lead 2x3 DFN
XXX
YWW
NN
1997-2012 Microchip Technology Inc.
Example:
274
527
I3
DS21189T-page 13
24AA64/24LC64/24FC64
8-Lead 2x3 TDFN
Example:
XXX
YWW
NN
A74
527
I3
5-Lead SOT-23
Example:
XXNN
7GNN
5-Lead Chip Scale
Example:
75
13
XW
NN
1st Line Marking Codes
Part Number TSSOP
TSSOP
X-Rotated
MSOP
4AB
4ABX
4A64T
24LC64
4LB
4LBX
24FC64
4FB
—
24AA64
Note:
DFN
TDFN
SOT-23
I Temp.
E Temp.
I Temp.
E Temp.
I Temp.
E Temp.
271
—
A71
E10
7HNN
7WNN
4L64T
274
275
A74
A75
7GNN
7JNN
4F64T
27A
—
A7A
—
—
—
T = Temperature grade (I, E)
Legend: XX...X
T
Y
YY
WW
NNN
e3
Part number or part number code
Temperature (I, E)
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code (2 characters for small packages)
Pb-free JEDEC designator for Matte Tin (Sn)
Note:
For very small packages with no room for the Pb-free JEDEC designator
e3 , the marking will only appear on the outer carton or reel label.
Note:
In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
DS21189T-page 14
1997-2012 Microchip Technology Inc.
24AA64/24LC64/24FC64
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