24LC21/PROC [MICROCHIP]

128 X 8 I2C/2-WIRE SERIAL EEPROM, PDIP8, 0.300 INCH, PLASTIC, MS-001, DIP-8;
24LC21/PROC
型号: 24LC21/PROC
厂家: MICROCHIP    MICROCHIP
描述:

128 X 8 I2C/2-WIRE SERIAL EEPROM, PDIP8, 0.300 INCH, PLASTIC, MS-001, DIP-8

可编程只读存储器 电动程控只读存储器 电可擦编程只读存储器 时钟 光电二极管 内存集成电路
文件: 总24页 (文件大小:371K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
Not recommended for new designs –  
Please use 24LCS21A.  
24LC21  
1K 2.5V Dual Mode I2CSerial EEPROM  
Features:  
Package Types  
PDIP  
• Single supply with operation down to 2.5V  
• Completely implements DDC1 /DDC2 interface  
for monitor identification  
NC  
NC  
1
2
8
7
VCC  
• Low-power CMOS technology:  
- 1 mA active current typical  
VCLK  
- 10 A standby current typical at 5.5V  
NC  
3
4
6
5
SCL  
SDA  
2
• 2-wire serial interface bus, I C compatible  
• Self-timed write cycle (including auto-erase)  
• Page-write buffer for up to 8 bytes  
VSS  
• 100 kHz (2.5V) and 400 kHz (5V) compatibility  
• Factory programming (QTP) available  
• 1,000,000 erase/write cycles ensured  
• Data retention > 200 years  
SOIC  
1
2
8
7
NC  
NC  
VCC  
• 8-pin PDIP and SOIC package  
VCLK  
• Available for extended temperature ranges  
Commercial (C):  
Industrial (I):  
0°C to +70°C  
-40°C to +85°C  
3
4
5
5
NC  
SCL  
SDA  
VSS  
Description:  
The Microchip Technology Inc. 24LC21 is a 128 x 8 bit  
Electrically Erasable PROM. This device is designed  
for use in applications requiring storage and serial  
transmission of configuration and control information.  
Two modes of operation have been implemented:  
Transmit-only mode and Bidirectional mode. Upon  
power-up, the device will be in the Transmit-only mode,  
sending a serial bit stream of the entire memory array  
contents, clocked by the VCLK pin. A valid high-to-low  
transition on the SCL pin will cause the device to enter  
the Bidirectional mode, with byte selectable read/write  
capability of the memory array. The 24LC21 is available  
in a standard 8-pin PDIP and SOIC package, in both  
commercial and industrial temperature ranges.  
Block Diagram  
VCLK  
HV Generator  
I/O  
Control  
Logic  
Memory  
Control  
Logic  
EEPROM  
Array  
XDEC  
Page Latches  
SDA SCL  
YDEC  
VCC  
VSS  
Sense Amp  
R/W Control  
1994-2012 Microchip Technology Inc.  
DS21095K-page 1  
24LC21  
1.0  
ELECTRICAL CHARACTERISTICS  
Absolute Maximum Ratings(†)  
VCC.............................................................................................................................................................................7.0V  
All inputs and outputs w.r.t. VSS ........................................................................................................ -0.6V to VCC + 1.0V  
Storage temperature ...............................................................................................................................-65°C to +150°C  
Ambient temperature with power applied................................................................................................-40°C to +125°C  
Soldering temperature of leads (10 seconds) .......................................................................................................+300°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 these or any other conditions above those  
indicated in the operational listings of this specification is not implied. Exposure to Absolute Maximum Rating  
conditions for extended periods may affect device reliability.  
TABLE 1-1:  
DC CHARACTERISTICS  
VCC = +2.5V to 5.5V  
DC CHARACTERISTICS  
Parameter  
Commercial (C): TA = 0°C to +70°C  
Industrial  
(I): TA = -40°C to +85°C  
Symbol  
Min  
Max  
Units  
Conditions  
SCL and SDA pins:  
High-level input voltage  
Low-level input voltage  
VIH  
VIL  
.7 VCC  
.3 VCC  
V
V
Input levels on VCLK pin:  
High-level input voltage  
Low-level input voltage  
VIH  
VIL  
2.0  
.8  
.2 VCC  
V
V
VCC 2.7V (Note 1)  
VCC < 2.7V (Note 1)  
Hysteresis of Schmitt Trigger inputs  
Low-level output voltage  
VHYS  
VOL1  
.05 VCC  
.4  
V
V
(Note 1)  
IOL = 3 mA, VCC = 2.5V (Note 1)  
IOL = 6 mA, VCC = 2.5V  
VIN = .1V to VCC  
Low-level output voltage  
VOL2  
.6  
V
Input leakage current  
ILI  
-10  
-10  
10  
10  
10  
A  
A  
pF  
Output leakage current  
ILO  
VOUT = .1V to VCC  
Pin capacitance (all inputs/outputs)  
CIN, COUT  
VCC = 5.0V (Note1),  
TA = 25C, FCLK = 1 MHz  
Operating current  
Standby current  
ICC Write  
ICC Read  
3
1
mA  
mA  
VCC = 5.5V, SCL = 400 kHz  
ICCS  
30  
100  
A  
A  
VCC = 3.0V, SDA = SCL = VCC  
VCC = 5.5V, SDA = SCL = VCC  
(Note 2)  
Note 1: This parameter is periodically sampled and not 100% tested.  
2: VLCK must be grounded.  
DS21095K-page 2  
1994-2012 Microchip Technology Inc.  
24LC21  
TABLE 1-2:  
AC CHARACTERISTICS  
Vcc= 4.5 - 5.5V  
Fast Mode  
Standard Mode  
Parameter  
Symbol  
Units  
Remarks  
Min  
Max  
Min  
Max  
Clock frequency  
FCLK  
THIGH  
TLOW  
TR  
4000  
4700  
100  
600  
1300  
400  
kHz  
ns  
Clock high time  
Clock low time  
ns  
SDA and SCL rise time  
SDA and SCL fall time  
Start condition hold time  
1000  
300  
300  
300  
ns  
(Note 1)  
(Note 1)  
TF  
ns  
THD:STA  
4000  
600  
ns  
After this period the first clock  
pulse is generated  
Start condition setup time  
TSU:STA  
4700  
600  
ns  
Only relevant for repeated  
Start condition  
Data input hold time  
Data input setup time  
Stop condition setup time  
Output valid from clock  
Bus free time  
THD:DAT  
TSU:DAT  
TSU:STO  
TAA  
0
0
ns  
ns  
ns  
ns  
ns  
(Note 2)  
250  
4000  
100  
600  
3500  
900  
(Note 2)  
TBUF  
4700  
1300  
Time the bus must be free  
before a new transmission  
can start  
Output fall time from VIH  
min. to VIL max.  
TOF  
TSP  
250  
50  
20 + .1  
CB  
250  
50  
ns  
ns  
(Note 1), CB 100 pF  
Input filter spike suppres-  
sion (SDA and SCL pins)  
(Note 3)  
Write cycle time  
TWR  
10  
10  
ms  
Byte or Page mode  
Transmit-only Mode Parameters  
Output valid from VCLK  
VCLK high time  
TVAA  
TVHIGH  
TVLOW  
TVHZ  
4000  
4700  
2000  
600  
1300  
1000  
ns  
ns  
ns  
ns  
ns  
VCLK low time  
Mode transition time  
500  
500  
Transmit-only power-up  
time  
TVPU  
0
0
Endurance  
1M  
1M  
cycles 25°C, VCC = 5.0V, Block  
mode (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 and 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  
1994-2012 Microchip Technology Inc.  
DS21095K-page 3  
24LC21  
mitted on the SDA pin in 8-bit bytes, each followed by  
a ninth, null bit (see Figure 2-1). The clock source for  
the Transmit-only mode is provided on the VCLK pin,  
and a data bit is output on the rising edge on this pin.  
The eight bits in each byte are transmitted Most Signif-  
icant bit first. Each byte within the memory array will be  
output in sequence. When the last byte in the memory  
array is transmitted, the output will wrap around to the  
first location and continue. The Bidirectional mode  
Clock (SCL) pin must be held high for the device to  
remain in the Transmit-only mode.  
2.0  
FUNCTIONAL DESCRIPTION  
The 24LC21 operates in two modes, the Transmit-only  
mode and the Bidirectional mode. There is a separate  
two-wire protocol to support each mode, each having a  
separate clock input and sharing a common data line  
(SDA). The device enters the Transmit-only mode upon  
power-up. In this mode, the device transmits data bits  
on the SDA pin in response to a clock signal on the  
VCLK pin. The device will remain in this mode until a  
valid high-to-low transition is placed on the SCL input.  
When a valid transition on SCL is recognized, the  
device will switch into the Bidirectional mode. The only  
way to switch the device back to the Transmit-only  
mode is to remove power from the device.  
2.2  
Initialization Procedure  
After VCC has stabilized, the device will be in the Trans-  
mit-only mode. Nine clock cycles on the VCLK pin must  
be given to the device for it to perform internal synchro-  
nization. During this period, the SDA pin will be in a  
high-impedance state. On the rising edge of the tenth  
clock cycle, the device will output the first valid data bit  
which will be the Most Significant bit of a byte. The  
device will power-up at an indeterminate byte address.  
(Figure 2-2).  
2.1  
Transmit-only Mode  
The device will power-up in the Transmit-only mode.  
This mode supports a unidirectional two-wire protocol  
for transmission of the contents of the memory array.  
This device requires that it be initialized prior to valid  
data being sent in the Transmit-only mode (see Initial-  
ization Procedure, below). In this mode, data is trans-  
FIGURE 2-1:  
TRANSMIT-ONLY MODE  
SCL  
TVAA  
TVAA  
SDA  
Null Bit  
Bit 1 (LSB)  
Bit 1 (MSB)  
Bit 7  
VCLK  
TVHIGH  
TVLOW  
FIGURE 2-2:  
DEVICE INITIALIZATION  
VCC  
SCL  
TVAA  
TVAA  
High-impedance for 9 clock cycles  
TVPU  
Bit 8  
Bit 7  
SDA  
VCLK  
1
2
8
9
10  
11  
DS21095K-page 4  
1994-2012 Microchip Technology Inc.  
24LC21  
3.1  
Bidirectional Mode Bus  
Characteristics  
3.0  
BIDIRECTIONAL MODE  
The 24LC21 can be switched into the Bidirectional  
mode (see Figure 3-1) by applying a valid high-to-low  
transition on the Bidirectional mode clock (SCL). When  
the device has been switched into the Bidirectional  
mode, the VCLK input is disregarded, with the exception  
that a logic high level is required to enable write capa-  
bility. This mode supports a two-wire bidirectional data  
transmission protocol. In this protocol, a device that  
sends data on the bus is defined to be the transmitter,  
and a device that receives data from the bus is defined  
to be the receiver. The bus must be controlled by a  
master device that generates the Bidirectional mode  
clock (SCL), controls access to the bus and generates  
the Start and Stop conditions, while the 24LC21 acts as  
the slave. Both master and slave can operate as  
transmitter or receiver, but the master device  
determines which mode is activated.  
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.  
Accordingly, the following bus conditions have been  
defined (see Figure 3-2).  
3.1.1  
BUS NOT BUSY (A)  
Both data and clock lines remain high.  
3.1.2  
A high-to-low transition of the SDA line while the clock  
(SCL) is high determines Start condition. All  
commands must be preceded by a Start condition.  
START DATA TRANSFER (B)  
a
3.1.3  
A low-to-high transition of the SDA line while the clock  
(SCL) is high determines Stop condition. All  
operations must be ended with a Stop condition.  
STOP DATA TRANSFER (C)  
a
FIGURE 3-1:  
MODE TRANSITION  
Transmit-only mode  
Bidirectional mode  
SCL  
TVHZ  
SDA  
VCLK  
FIGURE 3-2:  
DATA TRANSFER SEQUENCE ON THE SERIAL BUS  
(A)  
(B)  
(D)  
(D)  
(C) (A)  
SCL  
SDA  
Start  
Condition  
Stop  
Condition  
Address or  
Acknowledge  
Valid  
Data  
Allowed  
to Change  
1994-2012 Microchip Technology Inc.  
DS21095K-page 5  
24LC21  
3.1.4  
DATA VALID (D)  
3.1.5  
ACKNOWLEDGE  
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.  
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.  
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.  
Note:  
The 24LC21 does not generate any  
Acknowledge bits if an internal program-  
ming cycle is in progress.  
Each data transfer is initiated with a Start condition and  
terminated with a Stop condition. The number of the  
data bytes transferred between the Start and Stop  
conditions is determined by the master device and is  
theoretically unlimited, although only the last eight will  
be stored when doing a write operation. When an  
overwrite does occur, it will replace data in a first in first  
out fashion.  
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. 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 must leave the data line high to enable  
the master to generate the Stop condition.  
FIGURE 3-3:  
BUS TIMING START/STOP  
VHYS  
SCL  
THD:STA  
TSU:STA  
TSU:STO  
SDA  
Start  
Stop  
FIGURE 3-4:  
BUS TIMING DATA  
TR  
TF  
THIGH  
TLOW  
SCL  
TSU:STA  
THD:DAT  
TSU:DAT  
TSU:STO  
THD:STA  
SDA  
IN  
TSP  
TBUF  
TAA  
TAA  
THD:STA  
SDA  
OUT  
DS21095K-page 6  
1994-2012 Microchip Technology Inc.  
24LC21  
3.1.6  
SLAVE ADDRESS  
4.0  
4.1  
WRITE OPERATION  
Byte Write  
After generating a Start condition, the bus master trans-  
mits the slave address consisting of a 7-bit device code  
1010’ for the 24LC21, followed by three “don’t care”  
bits.  
Following the Start signal from the master, the slave  
address (4 bits), the “don’t care” bits (3 bits) and the  
R/W bit which is a logic low, is placed onto the bus by  
the master transmitter. This indicates to the  
addressed slave receiver that a byte with a word  
address will follow after it has generated an Acknowl-  
edge bit during the ninth clock cycle. Therefore, the  
next byte transmitted by the master is the word  
address and will be written into the address pointer of  
the 24LC21. After receiving another Acknowledge  
signal from the 24LC21 the master device will transmit  
the data word to be written into the addressed mem-  
ory location. The 24LC21 acknowledges again and  
the master generates a Stop condition. This initiates  
the internal write cycle, and during this time the  
24LC21 will not generate Acknowledge signals  
(Figure 4-1).  
The eighth bit of slave address determines if the master  
device wants to read or write to the 24LC21 (Figure 3-5).  
The 24LC21 monitors the bus for its corresponding  
slave address all the time. It generates an  
Acknowledge bit if the slave address was true and it is  
not in a programming mode.  
Operation Control Code  
Chip Select R/W  
Read  
Write  
1010  
1010  
xxx  
xxx  
1
0
FIGURE 3-5:  
CONTROL BYTE  
ALLOCATION  
Start  
Read/Write  
It is required that VCLK be held at a logic high level in  
order to program the device. This applies to byte write  
and page write operation. Note that VCLK can go low  
while the device is in its self-timed program operation  
and not affect programming.  
SLAVE ADDRESS  
R/W  
A
4.2  
Page Write  
1
0
1
0
x
x
x
The write control byte, word address and the first data  
byte are transmitted to the 24LC21 in the same way as  
in a byte write. But instead of generating a Stop condi-  
tion the master transmits up to eight data bytes to the  
24LC21, which are temporarily stored in the on-chip  
page buffer and will be written into the memory after the  
master has transmitted a Stop condition. After the  
receipt of each word, the three lower order address  
pointer bits are internally incremented by one. The  
higher order five bits of the word address remains  
constant. If the master should transmit more than eight  
words 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 4-3).  
1994-2012 Microchip Technology Inc.  
DS21095K-page 7  
24LC21  
It is required that VCLK be held at a logic high level in  
order to program the device. This applies to byte write  
and page write operation. Note that VCLK can go low  
while the device is in its self-timed program operation  
and not affect programming.  
Note:  
Page write operations are limited to writing  
bytes within single physical page,  
a
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.  
FIGURE 4-1:  
BYTE WRITE  
S
T
A
R
T
S
T
O
P
BUS ACTIVITY  
MASTER  
Control  
Byte  
Word  
Address  
Data  
SDA LINE  
S
P
A
C
K
A
C
K
A
C
K
BUS ACTIVITY  
VCLK  
FIGURE 4-2:  
BYTE WRITE  
S
T
A
R
T
S
T
O
P
BUS ACTIVITY  
MASTER  
Control  
Byte  
Word  
Address  
Data  
SDA LINE  
S
P
A
C
K
A
C
K
A
C
K
BUS ACTIVITY  
VCLK  
DS21095K-page 8  
1994-2012 Microchip Technology Inc.  
24LC21  
FIGURE 4-3:  
PAGE WRITE  
S
T
A
R
T
S
T
BUS ACTIVITY  
MASTER  
Control  
Byte  
Word  
Address  
O
Data (n)  
Data (n + 1)  
Data (n + 15)  
P
SDA LINE  
S
P
A
C
K
A
C
K
A
C
K
A
C
K
A
C
K
BUS ACTIVITY  
VCLK  
1994-2012 Microchip Technology Inc.  
DS21095K-page 9  
24LC21  
5.0  
ACKNOWLEDGE POLLING  
6.0  
WRITE PROTECTION  
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. ACK polling  
can 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 the cycle is complete, then the device will return the  
ACK and the master can then proceed with the next  
Read or Write command. See Figure 5-1 for the flow  
diagram.  
When using the 24LC21 in the Bidirectional mode, the  
VCLK pin operates as the write-protect control pin.  
Setting VCLK high allows normal write operations, while  
setting VCLK low prevents writing to any location in the  
array. Connecting the VCLK pin to VSS would allow the  
24LC21 to operate as a serial ROM, although this  
configuration would prevent using the device in the  
Transmit-only mode.  
FIGURE 5-1:  
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  
DS21095K-page 10  
1994-2012 Microchip Technology Inc.  
24LC21  
7.3  
Sequential Read  
7.0  
READ OPERATION  
Sequential reads are initiated in the same way as a  
random read except that after the 24LC21 transmits the  
first data byte, the master issues an acknowledge as  
opposed to a Stop condition in a random read. This  
directs the 24LC21 to transmit the next sequentially  
addressed 8-bit word (see Figure 7-3).  
Read operations are initiated in the same way as write  
operations with the exception that the R/W bit of the  
slave address is set to ‘1’. There are three basic types  
of read operations: current address read, random read  
and sequential read.  
7.1  
Current Address Read  
To provide sequential reads the 24LC21 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 24LC21 contains an address counter that  
maintains the address of the last word accessed, inter-  
nally incremented by one. Therefore, if the previous  
access (either a read or write operation) was to  
address n, the next current address read operation  
would access data from address n + 1. Upon receipt of  
the slave address with R/W bit set to ‘1’, the 24LC21  
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 24LC21  
discontinues transmission (Figure 7-1).  
7.4  
Noise Protection  
The 24LC21 employs a VCC threshold detector circuit  
which disables the internal erase/write logic if the VCC  
is below 1.5 volts at nominal conditions.  
The SCL and SDA inputs have Schmitt Trigger and  
filter circuits which suppress noise spikes to assure  
proper device operation even on a noisy bus.  
7.2  
Random Read  
Random read operations allow the master to access  
any memory location in a random manner. To perform  
this type of read operation, first the word address must  
be set. This is done by sending the word address to the  
24LC21 as part of a write operation. After the word  
address is sent, the master generates a Start condition  
following the acknowledge. This terminates the write  
operation, but not before the internal address pointer is  
set. Then the master issues the control byte again but  
with the R/W bit set to a ‘1’. The 24LC21 will then issue  
an acknowledge and transmits the eight bit data word.  
The master will not acknowledge the transfer but does  
generate  
a
Stop condition and the 24LC21  
discontinues transmission (Figure 7-2).  
FIGURE 7-1:  
CURRENT ADDRESS READ  
S
T
A
R
T
S
T
O
P
BUS ACTIVITY  
MASTER  
Control  
Byte  
Data (n)  
SDA LINE  
S
P
N
O
A
C
K
BUS ACTIVITY  
A
C
K
1994-2012 Microchip Technology Inc.  
DS21095K-page 11  
24LC21  
FIGURE 7-2:  
RANDOM READ  
S
T
A
R
T
S
T
A
R
T
S
T
O
P
Control  
Byte  
Word  
Address  
Control  
Byte  
BUS ACTIVITY  
MASTER  
Data (n)  
S
P
S
SDA LINE  
A
C
K
A
C
K
A
C
K
N
O
BUS ACTIVITY  
A
C
K
FIGURE 7-3:  
SEQUENTIAL READ  
S
T
O
P
BUS ACTIVITY  
MASTER  
Control  
Byte  
Data (n)  
Data (n + 1)  
Data (n + 2)  
Data (n + X)  
SDA LINE  
P
A
C
K
A
C
K
A
C
K
A
C
K
N
O
BUS ACTIVITY  
A
C
K
DS21095K-page 12  
1994-2012 Microchip Technology Inc.  
24LC21  
8.2  
SCL  
8.0  
PIN DESCRIPTIONS  
This pin is the clock input for the Bidirectional mode,  
and is used to synchronize data transfer to and from the  
device. It is also used as the signaling input to switch  
the device from the Transmit-only mode to the  
Bidirectional mode. It must remain high for the chip to  
continue operation in the Transmit-only mode.  
TABLE 8-1:  
Name  
PIN FUNCTION TABLE  
Function  
VSS  
SDA  
SCL  
VCLK  
VCC  
NC  
Ground  
Serial Address/Data I/O  
Serial Clock (Bidirectional mode)  
Serial Clock (Transmit-only mode)  
+2.5V to 5.5V Power Supply  
No Connection  
8.3  
VCLK  
This pin is the clock input for the Transmit-only mode.  
In the Transmit-only mode, each bit is clocked out on  
the rising edge of this signal. In the Bidirectional mode,  
a high logic level is required on this pin to enable write  
capability.  
8.1  
SDA  
This pin is used to transfer addresses and data into and  
out of the device, when the device is in the Bidirectional  
mode. In the Transmit-only mode, which only allows  
data to be read from the device, data is also transferred  
on the SDA pin. This pin is an open drain terminal,  
therefore the SDA bus requires a pull-up resistor to  
VCC (typical 10Kfor 100 kHz, 2Kfor 400 kHz).  
For normal data transfer in the Bidirectional mode, SDA  
is allowed to change only during SCL low. Changes  
during SCL high are reserved for indicating the Start  
and Stop conditions.  
1994-2012 Microchip Technology Inc.  
DS21095K-page 13  
24LC21  
9.0  
9.1  
PACKAGING INFORMATION  
Package Marking Information  
8-Lead PDIP  
Example  
24LC21  
XXXXXXXX  
XXXXXNNN  
YYWW  
017  
0410  
Example  
8-Lead SOIC (.150”)  
24LC21  
/SN0410  
017  
XXXXXXXX  
XXXXYYWW  
NNN  
Legend: XX...X Customer-specific information  
Y
YY  
WW  
NNN  
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  
e
3
Pb-free JEDEC designator for Matte Tin (Sn)  
*
This package is Pb-free. The Pb-free JEDEC designator (  
can be found on the outer packaging for this package.  
)
e3  
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.  
DS21095K-page 14  
1994-2012 Microchip Technology Inc.  
24LC21  
8-Lead Plastic Dual In-line (P) – 300 mil Body (PDIP)  
Note: For the most current package drawings, please see the Microchip Packaging Specification located  
at http://www.microchip.com/packaging  
E1  
D
2
n
1
E
A2  
A
L
c
A1  
B1  
B
p
eB  
Units  
INCHES*  
NOM  
8
MILLIMETERS  
Dimension Limits  
MIN  
MAX  
MIN  
NOM  
8
MAX  
n
p
Number of Pins  
Pitch  
.100  
2.54  
Top to Seating Plane  
A
.140  
.155  
.130  
.170  
3.56  
2.92  
3.94  
3.30  
4.32  
Molded Package Thickness  
Base to Seating Plane  
Shoulder to Shoulder Width  
Molded Package Width  
Overall Length  
A2  
A1  
E
.115  
.015  
.300  
.240  
.360  
.125  
.008  
.045  
.014  
.310  
5
.145  
3.68  
0.38  
7.62  
6.10  
9.14  
3.18  
0.20  
1.14  
0.36  
7.87  
5
.313  
.250  
.373  
.130  
.012  
.058  
.018  
.370  
10  
.325  
.260  
.385  
.135  
.015  
.070  
.022  
.430  
15  
7.94  
6.35  
9.46  
3.30  
0.29  
1.46  
0.46  
9.40  
10  
8.26  
6.60  
9.78  
3.43  
0.38  
1.78  
0.56  
10.92  
15  
E1  
D
Tip to Seating Plane  
Lead Thickness  
L
c
Upper Lead Width  
B1  
B
Lower Lead Width  
Overall Row Spacing  
Mold Draft Angle Top  
Mold Draft Angle Bottom  
§
eB  
5
10  
15  
5
10  
15  
* Controlling Parameter  
§ Significant Characteristic  
Notes:  
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed  
.010” (0.254mm) per side.  
JEDEC Equivalent: MS-001  
Drawing No. C04-018  
1994-2012 Microchip Technology Inc.  
DS21095K-page 15  
24LC21  
8-Lead Plastic Small Outline (SN) – Narrow, 150 mil Body (SOIC)  
Note: For the most current package drawings, please see the Microchip Packaging Specification located  
at http://www.microchip.com/packaging  
E
E1  
p
D
2
B
n
1
h
45  
c
A2  
A
L
A1  
Units  
INCHES*  
MILLIMETERS  
Dimension Limits  
MIN  
NOM  
8
MAX  
MIN  
NOM  
8
MAX  
n
p
Number of Pins  
Pitch  
.050  
1.27  
Overall Height  
A
.053  
.061  
.056  
.007  
.237  
.154  
.193  
.015  
.025  
4
.069  
1.35  
1.32  
1.55  
1.42  
0.18  
6.02  
3.91  
4.90  
0.38  
0.62  
4
1.75  
Molded Package Thickness  
Standoff  
A2  
A1  
E
.052  
.004  
.228  
.146  
.189  
.010  
.019  
0
.061  
.010  
.244  
.157  
.197  
.020  
.030  
8
1.55  
0.25  
6.20  
3.99  
5.00  
0.51  
0.76  
8
§
0.10  
5.79  
3.71  
4.80  
0.25  
0.48  
0
Overall Width  
Molded Package Width  
Overall Length  
E1  
D
Chamfer Distance  
Foot Length  
h
L
Foot Angle  
c
Lead Thickness  
Lead Width  
.008  
.013  
0
.009  
.017  
12  
.010  
.020  
15  
0.20  
0.33  
0
0.23  
0.42  
12  
0.25  
0.51  
15  
B
Mold Draft Angle Top  
Mold Draft Angle Bottom  
0
12  
15  
0
12  
15  
* Controlling Parameter  
§ Significant Characteristic  
Notes:  
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed  
.010” (0.254mm) per side.  
JEDEC Equivalent: MS-012  
Drawing No. C04-057  
DS21095K-page 16  
1994-2012 Microchip Technology Inc.  
24LC21  
APPENDIX A: REVISION HISTORY  
Revision J  
Added note to page 1 header (Not recommended for  
new designs).  
Added Section 9.0: Package Marking Information.  
Added On-line Support page.  
Updated document format.  
Revision K  
Added a note to each package outline drawing.  
1994-2012 Microchip Technology Inc.  
DS21095K-page 17  
24LC21  
NOTES:  
DS21095K-page 18  
1994-2012 Microchip Technology Inc.  
24LC21  
THE MICROCHIP WEB SITE  
CUSTOMER SUPPORT  
Microchip provides online support via our WWW site at  
www.microchip.com. This web site is used as a means  
to make files and information easily available to  
customers. Accessible by using your favorite Internet  
browser, the web site contains the following  
information:  
Users of Microchip products can receive assistance  
through several channels:  
• Distributor or Representative  
• Local Sales Office  
• Field Application Engineer (FAE)  
Technical Support  
Product Support – Data sheets and errata,  
application notes and sample programs, design  
resources, user’s guides and hardware support  
documents, latest software releases and archived  
software  
Customers  
should  
contact  
their  
distributor,  
representative or field application engineer (FAE) for  
support. Local sales offices are also available to help  
customers. A listing of sales offices and locations is  
included in the back of this document.  
General Technical Support – Frequently Asked  
Questions (FAQ), technical support requests,  
online discussion groups, Microchip consultant  
program member listing  
Technical support is available through the web site  
at: http://microchip.com/support  
Business of Microchip – Product selector and  
ordering guides, latest Microchip press releases,  
listing of seminars and events, listings of  
Microchip sales offices, distributors and factory  
representatives  
CUSTOMER CHANGE NOTIFICATION  
SERVICE  
Microchip’s customer notification service helps keep  
customers current on Microchip products. Subscribers  
will receive e-mail notification whenever there are  
changes, updates, revisions or errata related to a  
specified product family or development tool of interest.  
To register, access the Microchip web site at  
www.microchip.com. Under “Support”, click on  
“Customer Change Notification” and follow the  
registration instructions.  
1994-2012 Microchip Technology Inc.  
DS21095K-page 19  
24LC21  
READER RESPONSE  
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip  
product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our  
documentation can better serve you, please FAX your comments to the Technical Publications Manager at  
(480) 792-4150.  
Please list the following information, and use this outline to provide us with your comments about this document.  
TO:  
RE:  
Technical Publications Manager  
Reader Response  
Total Pages Sent ________  
From:  
Name  
Company  
Address  
City / State / ZIP / Country  
Telephone: (_______) _________ - _________  
FAX: (______) _________ - _________  
Literature Number: DS21095K  
Application (optional):  
Would you like a reply?  
Y
N
Device: 24LC21  
Questions:  
1. What are the best features of this document?  
2. How does this document meet your hardware and software development needs?  
3. Do you find the organization of this document easy to follow? If not, why?  
4. What additions to the document do you think would enhance the structure and subject?  
5. What deletions from the document could be made without affecting the overall usefulness?  
6. Is there any incorrect or misleading information (what and where)?  
7. How would you improve this document?  
DS21095K-page 20  
1994-2012 Microchip Technology Inc.  
24LC21  
PRODUCT IDENTIFICATION SYSTEM  
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.  
PART NO.  
Device  
X
/XX  
XXX  
Temperature  
Range  
Package  
Pattern  
2
Device  
24LC21: Dual Mode I C Serial EEPROM  
2
24LC21T: Dual Mode I C Serial EEPROM (Tape and Reel)  
Temperature Range Blank  
I
=
=
0C to +70C  
-40C to +85C  
Package  
P
SN  
=
=
Plastic DIP (300 mil Body), 8-lead  
Plastic SOIC (150 mil Body), 8-lead  
Sales and Support  
Data Sheets  
Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and  
recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following:  
1. Your local Microchip sales office  
2. The Microchip Worldwide Site (www.microchip.com)  
Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using.  
New Customer Notification System  
Register on our web site (www.microchip.com/cn) to receive the most current information on our products.  
1994-2012 Microchip Technology Inc.  
DS21095K-page 21  
24LC21  
NOTES:  
DS21095K-page 22  
1994-2012 Microchip Technology Inc.  
Note the following details of the code protection feature on Microchip devices:  
Microchip products meet the specification contained in their particular Microchip Data Sheet.  
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the  
intended manner and under normal conditions.  
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our  
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data  
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.  
Microchip is willing to work with the customer who is concerned about the integrity of their code.  
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not  
mean that we are guaranteeing the product as “unbreakable.”  
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our  
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts  
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.  
Information contained in this publication regarding device  
applications and the like is provided only for your convenience  
and may be superseded by updates. It is your responsibility to  
ensure that your application meets with your specifications.  
MICROCHIP MAKES NO REPRESENTATIONS OR  
WARRANTIES OF ANY KIND WHETHER EXPRESS OR  
IMPLIED, WRITTEN OR ORAL, STATUTORY OR  
OTHERWISE, RELATED TO THE INFORMATION,  
INCLUDING BUT NOT LIMITED TO ITS CONDITION,  
QUALITY, PERFORMANCE, MERCHANTABILITY OR  
FITNESS FOR PURPOSE. Microchip disclaims all liability  
arising from this information and its use. Use of Microchip  
devices in life support and/or safety applications is entirely at  
the buyer’s risk, and the buyer agrees to defend, indemnify and  
hold harmless Microchip from any and all damages, claims,  
suits, or expenses resulting from such use. No licenses are  
conveyed, implicitly or otherwise, under any Microchip  
intellectual property rights.  
Trademarks  
The Microchip name and logo, the Microchip logo, dsPIC,  
FlashFlex, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro,  
PICSTART, PIC32 logo, rfPIC, SST, SST Logo, SuperFlash  
and UNI/O are registered trademarks of Microchip Technology  
Incorporated in the U.S.A. and other countries.  
FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor,  
MTP, SEEVAL and The Embedded Control Solutions  
Company are registered trademarks of Microchip Technology  
Incorporated in the U.S.A.  
Silicon Storage Technology is a registered trademark of  
Microchip Technology Inc. in other countries.  
Analog-for-the-Digital Age, Application Maestro, BodyCom,  
chipKIT, chipKIT logo, CodeGuard, dsPICDEM,  
dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,  
ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial  
Programming, ICSP, Mindi, MiWi, MPASM, MPF, MPLAB  
Certified logo, MPLIB, MPLINK, mTouch, Omniscient Code  
Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit,  
PICtail, REAL ICE, rfLAB, Select Mode, SQI, Serial Quad I/O,  
Total Endurance, TSHARC, UniWinDriver, WiperLock, ZENA  
and Z-Scale are trademarks of Microchip Technology  
Incorporated in the U.S.A. and other countries.  
SQTP is a service mark of Microchip Technology Incorporated  
in the U.S.A.  
GestIC and ULPP are registered trademarks of Microchip  
Technology Germany II GmbH & Co. & KG, a subsidiary of  
Microchip Technology Inc., in other countries.  
All other trademarks mentioned herein are property of their  
respective companies.  
© 1994-2012, Microchip Technology Incorporated, Printed in  
the U.S.A., All Rights Reserved.  
Printed on recycled paper.  
ISBN: 9781620767306  
QUALITY MANAGEMENT SYSTEM  
CERTIFIED BY DNV  
Microchip received ISO/TS-16949:2009 certification for its worldwide  
headquarters, design and wafer fabrication facilities in Chandler and  
Tempe, Arizona; Gresham, Oregon and design centers in California  
and India. The Company’s quality system processes and procedures  
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping  
devices, Serial EEPROMs, microperipherals, nonvolatile memory and  
analog products. In addition, Microchip’s quality system for the design  
and manufacture of development systems is ISO 9001:2000 certified.  
== ISO/TS 16949 ==  
1994-2012 Microchip Technology Inc.  
DS21095K-page 23  
Worldwide Sales and Service  
AMERICAS  
ASIA/PACIFIC  
ASIA/PACIFIC  
EUROPE  
Corporate Office  
2355 West Chandler Blvd.  
Chandler, AZ 85224-6199  
Tel: 480-792-7200  
Fax: 480-792-7277  
Technical Support:  
http://www.microchip.com/  
support  
Asia Pacific Office  
Suites 3707-14, 37th Floor  
Tower 6, The Gateway  
Harbour City, Kowloon  
Hong Kong  
Tel: 852-2401-1200  
Fax: 852-2401-3431  
India - Bangalore  
Tel: 91-80-3090-4444  
Fax: 91-80-3090-4123  
Austria - Wels  
Tel: 43-7242-2244-39  
Fax: 43-7242-2244-393  
Denmark - Copenhagen  
Tel: 45-4450-2828  
Fax: 45-4485-2829  
India - New Delhi  
Tel: 91-11-4160-8631  
Fax: 91-11-4160-8632  
France - Paris  
Tel: 33-1-69-53-63-20  
Fax: 33-1-69-30-90-79  
India - Pune  
Tel: 91-20-2566-1512  
Fax: 91-20-2566-1513  
Australia - Sydney  
Tel: 61-2-9868-6733  
Fax: 61-2-9868-6755  
Web Address:  
www.microchip.com  
Germany - Munich  
Tel: 49-89-627-144-0  
Fax: 49-89-627-144-44  
Japan - Osaka  
Tel: 81-66-152-7160  
Fax: 81-66-152-9310  
Atlanta  
Duluth, GA  
Tel: 678-957-9614  
Fax: 678-957-1455  
China - Beijing  
Tel: 86-10-8569-7000  
Fax: 86-10-8528-2104  
Italy - Milan  
Tel: 39-0331-742611  
Fax: 39-0331-466781  
Japan - Yokohama  
Tel: 81-45-471- 6166  
Fax: 81-45-471-6122  
China - Chengdu  
Tel: 86-28-8665-5511  
Fax: 86-28-8665-7889  
Boston  
Westborough, MA  
Tel: 774-760-0087  
Fax: 774-760-0088  
Netherlands - Drunen  
Tel: 31-416-690399  
Fax: 31-416-690340  
Korea - Daegu  
Tel: 82-53-744-4301  
Fax: 82-53-744-4302  
China - Chongqing  
Tel: 86-23-8980-9588  
Fax: 86-23-8980-9500  
Chicago  
Itasca, IL  
Tel: 630-285-0071  
Fax: 630-285-0075  
Spain - Madrid  
Tel: 34-91-708-08-90  
Fax: 34-91-708-08-91  
Korea - Seoul  
China - Hangzhou  
Tel: 86-571-2819-3187  
Fax: 86-571-2819-3189  
Tel: 82-2-554-7200  
Fax: 82-2-558-5932 or  
82-2-558-5934  
UK - Wokingham  
Tel: 44-118-921-5869  
Fax: 44-118-921-5820  
Cleveland  
Independence, OH  
Tel: 216-447-0464  
Fax: 216-447-0643  
China - Hong Kong SAR  
Tel: 852-2401-1200  
Fax: 852-2401-3431  
Malaysia - Kuala Lumpur  
Tel: 60-3-6201-9857  
Fax: 60-3-6201-9859  
Dallas  
Addison, TX  
Tel: 972-818-7423  
Fax: 972-818-2924  
China - Nanjing  
Tel: 86-25-8473-2460  
Fax: 86-25-8473-2470  
Malaysia - Penang  
Tel: 60-4-227-8870  
Fax: 60-4-227-4068  
China - Qingdao  
Tel: 86-532-8502-7355  
Fax: 86-532-8502-7205  
Philippines - Manila  
Tel: 63-2-634-9065  
Fax: 63-2-634-9069  
Detroit  
Farmington Hills, MI  
Tel: 248-538-2250  
Fax: 248-538-2260  
China - Shanghai  
Tel: 86-21-5407-5533  
Fax: 86-21-5407-5066  
Singapore  
Tel: 65-6334-8870  
Fax: 65-6334-8850  
Indianapolis  
Noblesville, IN  
Tel: 317-773-8323  
Fax: 317-773-5453  
China - Shenyang  
Tel: 86-24-2334-2829  
Fax: 86-24-2334-2393  
Taiwan - Hsin Chu  
Tel: 886-3-5778-366  
Fax: 886-3-5770-955  
Los Angeles  
China - Shenzhen  
Tel: 86-755-8203-2660  
Fax: 86-755-8203-1760  
Taiwan - Kaohsiung  
Tel: 886-7-213-7828  
Fax: 886-7-330-9305  
Mission Viejo, CA  
Tel: 949-462-9523  
Fax: 949-462-9608  
China - Wuhan  
Tel: 86-27-5980-5300  
Fax: 86-27-5980-5118  
Taiwan - Taipei  
Tel: 886-2-2508-8600  
Fax: 886-2-2508-0102  
Santa Clara  
Santa Clara, CA  
Tel: 408-961-6444  
Fax: 408-961-6445  
China - Xian  
Tel: 86-29-8833-7252  
Fax: 86-29-8833-7256  
Thailand - Bangkok  
Tel: 66-2-694-1351  
Fax: 66-2-694-1350  
Toronto  
Mississauga, Ontario,  
Canada  
China - Xiamen  
Tel: 905-673-0699  
Fax: 905-673-6509  
Tel: 86-592-2388138  
Fax: 86-592-2388130  
China - Zhuhai  
Tel: 86-756-3210040  
Fax: 86-756-3210049  
10/26/12  
DS21095K-page 24  
1994-2012 Microchip Technology Inc.  

相关型号:

24LC21/SN

I2C Serial EEPROM
ETC

24LC21/SNROC

128 X 8 I2C/2-WIRE SERIAL EEPROM, PDSO8, 0.150 INCH, PLASTIC, MS-012, SOIC-8
MICROCHIP

24LC21A

1K 2.5V Dual Mode I 2 C Serial EEPROM
MICROCHIP

24LC21A-I

1K 2.5V Dual Mode I2C Serial EEPROM
MICROCHIP

24LC21A-I-P

1K 2.5V Dual Mode I2C Serial EEPROM
MICROCHIP

24LC21A-I-SN

1K 2.5V Dual Mode I2C Serial EEPROM
MICROCHIP

24LC21A-I/P

1K 2.5V Dual Mode I2C™ Serial EEPROM
MICROCHIP

24LC21A-I/PG

128 X 8 I2C/2-WIRE SERIAL EEPROM, PDIP8, 0.300 INCH, ROHS COMPLIANT, PLASTIC, DIP-8
MICROCHIP

24LC21A-I/PREL

128 X 8 I2C/2-WIRE SERIAL EEPROM, PDIP8, 0.300 INCH, ROHS COMPLIANT, PLASTIC, DIP-8
MICROCHIP

24LC21A-I/SN

1K 2.5V Dual Mode I2C™ Serial EEPROM
MICROCHIP

24LC21A-I/SNG

128 X 8 I2C/2-WIRE SERIAL EEPROM, PDSO8, 3.90 MM, ROHS COMPLIANT, PLASTIC, SOIC-8
MICROCHIP

24LC21A-I/SNROC

128 X 8 I2C/2-WIRE SERIAL EEPROM, PDSO8, 3.90 MM, ROHS COMPLIANT, PLASTIC, SOIC-8
MICROCHIP