Shanghai Belling Corp., Ltd
BL24C02/04/08/16
BL24C02/BL24C04/BL24C08/BL24C16
2K bits (256 X 8) / 4K bits (512 X 8) / 8K bits (1024 X 8) / 16K bits (2048 X 8)
Two-wire Serial EEPROM
Features
Two-wire Serial Interface
VCC = 1.7V to 5.5V
Bi-directional Data Transfer Protocol
Internally Organized
BL24C02, 256 X 8 (2K bits)
BL24C04, 512 X 8 (4K bits)
BL24C08, 1024 X 8 (8K bits)
BL24C16, 2048 X 8 (16K bits)
1 MHz (5V), 400 kHz (1.8V, 2.5V, 2.7V) Compatibility
8-byte Page (2K), 16-byte Page (4K, 8K, 16K) Write Modes
Self-timed Write Cycle (5 ms max)
1 Million Write Cycles guaranteed
Data Retention > 100 Years
Operating Temperature: -40℃ to +85℃
8-lead PDIP, 8-lead SOP , 5-lead TSOT 23-5
and 8-lead TSSOP Packages
5-lead TSOT23-5
Description
BL24C02/BL24C04/BL24C08/BL24C16 provides 2048/4096/8192/16384 bits of serial electrically
erasable and programmable read-only memory (EEPROM) organized as 256/512/1024/2048 words of 8
bits each. The device is optimized for use in many industrial and commercial applications where
low-power and low-voltage operations are essential. The BL24C02/BL24C04/BL24C08/BL24C16 is
available in space-saving 8-lead PDIP, 8-lead SOP, 8-lead TSSOP and 5-lead TSOT23-5
packages
and is accessed via a two-wire serial interface.
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BL24C02/04/08/16
Pin Descriptions
Block Diagram
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BL24C02/04/08/16
DEVICE/PAGE ADDRESSES (A2, A1 and A0): The A2, A1 and A0 pins are device address inputs that
are hard wired for the BL24C02. Eight 2K devices may be addressed on a single bus system (device
addressing is discussed in detail under the Device Addressing section).
The BL24C04 uses the A2 and A1 inputs for hard wire addressing and a total of four 4K devices may be
addressed on a single bus system. The A0 pin is a no connect and can be connected to ground.
The BL24C08 only uses the A2 input for hardwire addressing and a total of two 8K devices may be
addressed on a single bus system. The A0 and A1 pins are no connects and can be connected to
ground.
The
BL24C16 does not use the device address pins, which limits the number of devices on a single bus
to one. The A0, A1 and A2 pins are no connects and can be connected to ground.
SERIAL DATA (SDA): The SDA pin is bi-directional 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.
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.
WRITE PROTECT (WP): The BL24C02/BL24C04/BL24C08/BL24C16 has a Write Protect pin that
provides hardware data protection. The Write Protect pin allows normal read/write operations when
connected to ground (GND). When the Write Protect pin is connected to VCC, the write protection feature
is enabled and operates as shown in the following Table 2.
WP Pin Status:
At VCC
Part of the Array Protected
BL24C02
Full (2K)
Array
At GND
BL 24C04
BL 24C08
BL 24C16
Full (4K)
Full (8K)
Full (16K)
Array
Array
Array
Normal Read/Write Operations
Memory Organization
BL24C02, 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.
BL24C04, 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.
BL24C08, 8K SERIAL EEPROM: Internally organized with 64 pages of 16 bytes each, the 8K requires a
10-bit data word address for random word addressing.
BL24C16, 16K SERIAL EEPROM: Internally organized with 128 pages of 16 bytes each, the 16K
requires an 11-bit data word address for random word addressing.
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Device Operation
CLOCK and DATA TRANSITIONS: The SDA pin is normally pulled high with an external device. Data
on the SDA pin may change only during SCL low time periods (see to Figure 1 on page 4). 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 (see to Figure 2 on page 4).
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 2 on page
4).
ACKNOWLEDGE: All addresses and data words are serially transmitted to and from the EEPROM in
8-bit words. The EEPROM sends a "0" to acknowledge that it has received each word. This happens
during the ninth clock cycle. STANDBY MODE: The K24C02/K24C04/K24C08/K24C16 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 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.
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BL24C02/04/08/16
Device Addressing
The 2K, 4K, 8K and 16K EEPROM devices all require an 8-bit device address word following a start
condition to enable the chip for a read or write operation (see to Figure 4 on page 7).
The device address word consists of a mandatory "1", "0" sequence for the first four most significant bits
as shown. This is common to all the Serial EEPROM devices.
The next 3 bits are the A2, A1 and A0 device address bits for the 2K EEPROM. These 3 bits must
compare to their corresponding hardwired input pins.
The 4K EEPROM only uses the A2 and A1 device address bits with the third bit being a memory page
address bit. The two device address bits must compare to their corresponding hardwired input pins. The
A0 pin is no connect.
The 8K EEPROM only uses the A2 device address bit with the next 2 bits being for memory page
addressing. The A2 bit must compare to its corresponding hard-wired input pin. The A1 and A0 pins are
no connect.
The 16K does not use any device address bits but instead the 3 bits are used for memory page
addressing. These page addressing bits on the 4K, 8K and 16K devices should be considered the most
significant bits of the data word address which follows. The A0, A1 and A2 pins are no connect.
The eighth bit of the device address is the read/write operation select bit. A read operation is initiated if
this bit is high and a write operation is initiated if this bit is low.
Upon a compare of the device address, the EEPROM will output a "0". If a compare is not made, the chip
will return to a standby state.
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Write Operations
BYTE WRITE: A write operation requires an 8-bit data word address following the device address word
and acknowledgment. Upon receipt of this address, the EEPROM will again respond with a "0" and then
clock in the first 8-bit data word. Following receipt of the 8-bit data word, the EEPROM will output a "0"
and the addressing device, such as a microcontroller, must terminate the write sequence with a stop
condition. At this time the EEPROM enters an internally timed write cycle, tWR, to the nonvolatile
memory. All inputs are disabled during this write cycle and the EEPROM will not respond until the write is
complete (see Figure 5 on page 7).
PAGE WRITE: The 2K EEPROM is capable of an 8-byte page write, and the 4K, 8K and 16K devices are
capable of 16-byte page writes.
A page write is initiated the same as a byte write, but the microcontroller does not send a stop condition
after the first data word is clocked in. Instead, after the EEPROM acknowledges receipt of the first data
word, the microcontroller can transmit up to seven (2K) or fifteen (4K, 8K, 16K) more data words. The
EEPROM will respond with a "0" after each data word received. The microcontroller must terminate the
page write sequence with a stop condition (see Figure 6 on page 7).
The data word address lower three (2K) or four (4K, 8K, 16K) bits are internally incremented following the
receipt of each data word. The higher data word address bits are not incremented, retaining the memory
page row location. When the word address, internally generated, reaches the page boundary, the
following byte is placed at the beginning of the same page. If more than eight (2K) or sixteen (4K, 8K,
16K) data words are transmitted to the EEPROM, the data word address will "roll over" and previous data
will be overwritten.
ACKNOWLEDGE POLLING: Once the internally timed write cycle has started and the EEPROM inputs
are disabled, acknowledge polling can be initiated. This involves sending a start condition followed by the
device address word. The read/write bit is representative of the operation desired. Only if the internal
write cycle has completed will the EEPROM respond with a "0", allowing the read or write sequence to
continue.
Read Operations
Read operations are initiated the same way as write operations with the exception that the read/write
select bit in the device address word is set to "1". There are three read operations: current address read,
random address read and sequential read.
CURRENT ADDRESS READ: The internal data word address counter maintains the last address
accessed during the last read or write operation, incremented by one. This address stays valid between
operations as long as the chip power is maintained. The address "roll over" during read is from the last
byte of the last memory page to the first byte of the first page. The address "roll over" during write is from
the last byte of the current page to the first byte of the same page.
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Once the device address with the read/write select bit set to "1" is clocked in and acknowledged by the
EEPROM, the current address data word is serially clocked out. The microcontroller does not respond
with an input "0" but does generate a following stop condition (see Figure 7 on page 8).
Read Operations
RANDOM READ: A random read requires a "dummy" byte write sequence to load in the data word
address. Once the device address word and data word address are clocked in and acknowledged by the
EEPROM, the microcontroller must generate another start condition. The microcontroller now initiates a
current address read by sending a device address with the read/write select bit high. The EEPROM
acknowledges the device address and serially clocks out the data word. The microcontroller does not
respond with a "0" but does generate a following stop condition (see Figure 8 on page 8).
SEQUENTIAL READ: Sequential reads are initiated by either a current address read or a random
address read. After the microcontroller receives a data word, it responds with an acknowledge. As long
as the EEPROM receives an acknowledge, it will continue to increment the data word address and
serially clock out sequential data words. When the memory address limit is reached, the data word
address will "roll over" and the sequential read will continue. The sequential read operation is terminated
when the microcontroller does not respond with a "0" but does generate a following stop condition (see
Figure 9 on page 8).
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Electrical Characteristics
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AC Electrical Characteristics
Bus Timing
Write Cycle Timing
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Package Information
8-lead PDIP Outline Dimensions
SYMBOL
A
A2
b
B1
c
c1
D
E1
e
eA
L
MIN
3.60
3.10
0.44
0.25
0.24
9.05
6.15
3.00
MILLIMETER
NOM
3.80
3.30
1.52BSC
0.25
9.25
6.35
2.54BSC
7.62BSC
-
MAX
4.00
3.50
0.53
0.31
0.26
9.45
6.55
-
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BL24C02/04/08/16
8-lead SOP Outline Dimensions
SYMBOL
A
A1
b
c
D
E
E1
e
Θ
MIN
0.08
0.44
0.21
4.70
5.80
3.70
0
MILLIMETER
NOM
0.18
4.90
6.00
3.90
1.27BSC
-
MAX
1.77
0.28
0.53
0.26
5.10
6.20
4.10
8°
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Shanghai Belling Corp., Ltd
BL24C02/04/08/16
8-lead TSSOP Outline Dimensions
SYMBOL
MILLIMETER
MIN
NOM
MAX
A
-
-
1.20
A1
0.05
-
0.15
A2
0.90
1.00
1.05
A3
0.34
0.44
0.54
b
0.20
-
0.28
b1
0.20
0.22
0.24
c
0.10
-
0.19
c1
0.10
0.13
0.15
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BL24C02/04/08/16
D
2.83
2.93
3.03
E
6.20
6.40
6.60
E1
4.30
4.40
4.50
e
L
0.65BSC
0.45
0.60
L1
1.00REF
L2
0.25BSC
0.75
R
0.09
-
-
R1
0.09
-
-
S
0.20
-
-
Θ1
0°
-
8°
Θ2
10°
12°
14°
Θ3
10°
12°
14°
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5-lead TSOT23-5 Outline Dimensions
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