Datasheet
Serial EEPROM Series Standard EEPROM
I2C BUS EEPROM (2-Wire)
BR24T256-W
General Description
BR24T256-W is a serial EEPROM of I2C BUS Interface Method
Packages W(Typ) x D(Typ) x H(Max)
Features
Completely conforming to the world standard I2C
BUS.
All controls available by 2 ports of serial clock
(SCL) and serial data (SDA)
Other devices than EEPROM can be connected to
the same port, saving microcontroller port
1.6V to 5.5V Single Power Source Operation most
suitable for battery use
1.6V to 5.5V wide limit of operating voltage, possible
FAST MODE 400KHz operation
Page Write Mode useful for initial value write at
factory shipment
Self-timed Programming Cycle
Low Current Consumption
Prevention of Write Mistake
¾ Write (Write Protect) Function added
¾ Prevention of Write Mistake at Low Voltage
More than 1 million write cycles
More than 40 years data retention
Noise filter built in SCL / SDA terminal
Initial delivery state FFh
DIP-T8
SSOP-B8
9.30mm x 6.50mm x 7.10mm
3.00mm x 6.40mm x 1.35mm
TSSOP-B8
SOP8
5.00mm x 6.20mm x 1.71mm
3.00mm x 6.40mm x 1.20mm
SOP- J8
4.90mm x 6.00mm x 1.65mm
Figure 1.
BR24T256-W
Capacity
256Kbit
Bit Format
32K×8
Type
Power Source
Voltage
Package
BR24T256-W
DIP-T8
BR24T256F-W
SOP8
BR24T256FJ-W
1.6V to 5.5V
SOP-J8
BR24T256FV-W
SSOP-B8
BR24T256FVT-W
TSSOP-B8
○Product structure：Silicon monolithic integrated circuit
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Datasheet
BR24T256-W
Absolute Maximum Ratings (Ta=25ºC)
Parameter
Symbol
Rating
Unit
Vcc
-0.3 to +6.5
V
Supply Voltage
Power Dissipation
Pd
Remark
450 (SOP8)
Derate by 4.5mW/°C when operating above Ta=25°C
450 (SOP-J8)
Derate by 4.5mW/°C when operating above Ta=25°C
300 (SSOP-B8)
mW
Derate by 3.0mW/°C when operating above Ta=25°C
330 (TSSOP-B8)
Derate by 3.3mW/°C when operating above Ta=25°C.
800 (DIP-T8)
Derate by 8.0mW/°C when operating above Ta=25°C
Storage Temperature
Tstg
-65 to +150
°C
Operating Temperature
Topr
-40 to +85
°C
‐
-0.3 to Vcc+1.0
V
The Max value of input voltage / output voltage is not over 6.5V.
When the pulse width is 50ns or less, the Min value of input voltage
/ output voltage is not lower than -1.0V.
Tjmax
150
°C
Junction temperature at the storage condition
VESD
-4000 to +4000
V
Input Voltage /
Output Voltage
Junction
Temperature
Electrostatic discharge
voltage
(human body model)
Memory Cell Characteristics (Ta=25ºC, Vcc=1.6V to 5.5V)
Parameter
Min
1,000,000
40
(1)
Write Cycles
Data Retention (1)
Limit
Typ
-
Max
-
Unit
Times
Years
(1) Not 100% TESTED
Recommended Operating Ratings
Parameter
Power Source Voltage
Input Voltage
Symbol
Vcc
VIN
Rating
1.6 to 5.5
0 to Vcc
Unit
V
DC Characteristics (Unless otherwise specified, Ta=-40ºC to +85ºC, Vcc=1.6V to 5.5V)
Parameter
Limit
Symbol
Min
Typ
Max
Unit
Conditions
Input High Voltage1
VIH1
0.7Vcc
-
Vcc+1.0
V
1.7V≦Vcc≦5.5V
Input Low Voltage1
VIL1
-0.3(2)
-
+0.3Vcc
V
1.7V≦Vcc≦5.5V
Input High Voltage2
VIH2
0.8Vcc
-
Vcc+1.0
V
1.6V≦Vcc＜1.7V
Input Low Voltage2
VIL2
-0.3(2)
-
+0.2Vcc
V
1.6V≦Vcc＜1.7V
Output Low Voltage1
VOL1
-
-
0.4
V
IOL=3.0mA, 2.5V≦Vcc≦5.5V (SDA)
Output Low Voltage2
VOL2
-
-
0.2
V
IOL=0.7mA, 1.6V≦Vcc＜2.5V (SDA)
Input Leakage Current
ILI
-1
-
+1
µA
VIN=0 to Vcc
Output Leakage Current
ILO
-1
-
+1
µA
Supply Current (Write)
ICC1
-
-
2.5
mA
Supply Current (Read)
ICC2
-
-
0.5
mA
Standby Current
ISB
-
-
2.0
µA
VOUT=0 to Vcc (SDA)
Vcc=5.5V, fSCL=400kHz, tWR=5ms,
Byte write, Page write
Vcc=5.5V, fSCL=400kHz
Random read, current read, sequential read
Vcc=5.5V, SDA・SCL=Vcc
A0,A1,A2=GND,WP=GND
(2) When the pulse width is 50ns or less, it is -1.0V.
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Datasheet
BR24T256-W
AC Characteristics (Unless otherwise specified, Ta=-40ºC to +85ºC, Vcc=1.6V to 5.5V)
Parameter
Limit
Symbol
Min
Typ
Max
Unit
Clock Frequency
fSCL
-
-
400
kHz
Data Clock High Period
tHIGH
0.6
-
-
µs
Data Clock Low Period
tLOW
1.2
-
-
µs
tR
-
-
1.0
µs
SDA,SCL (INPUT)Fall Time (1)
tF1
-
-
1.0
µs
SDA(OUTPUT)Fall Time (1)
tF2
-
-
0.3
µs
tHD:STA
0.6
-
-
µs
Start Condition Setup Time
tSU:STA
0.6
-
-
µs
Input Data Hold Time
tHD:DAT
0
-
-
ns
Input Data Setup Time
SDA,SCL(INPUT) Rise Time (1)
Start Condition Hold Time
tSU:DAT
100
-
-
ns
Output Data Delay Time
tPD
0.1
-
0.9
µs
Output Data Hold Time
tDH
0.1
-
-
µs
Stop Condition Setup Time
tSU:STO
0.6
-
-
µs
Bus Free Time
tBUF
1.2
-
-
µs
Write Cycle Time
tWR
-
-
5
ms
tI
-
-
0.1
µs
tHD:WP
1.0
-
-
µs
Noise Spike Width (SDA and SCL)
WP Hold Time
WP Setup Time
tSU:WP
0.1
-
-
µs
WP High Period
tHIGH:WP
1.0
-
-
µs
(1) Not 100% TESTED.
Condition Input Data Level:VIL=0.2×Vcc VIH=0.8×Vcc
Input Data Timing Reference Level: 0.3×Vcc/0.7×Vcc
Output Data Timing Reference Level: 0.3×Vcc/0.7×Vcc
Rise/Fall Time : ≦20ns
Serial Input / Output Timing
tR
SCL
30%
tHIGH
70%
30%
30%
tLOW
tHD:STA
70%
tF1
70% 70%
70%
70%
DATA(n)
DATA(1)
D0
D1
70%
ACK
ACK
tWR
70%
30%
30%
SDA
(入力)
(INPUT)
30%
tHD:DAT
tSU:DAT
70%
70%
70%
tDH
tPD
tBUF
30%
30%
70%
70%
SDA
(出力)
(OUTPUT)
30%
30%
tSU:WP
30%
○Input read at the rise edge of SCL
○Data output in sync with the fall of SCL
tHD:WP
STOP CONDITION
tF2
Figure 2-(d). WP Timing at Write Execution
Figure 2-(a). Serial Input / Output Timing
70%
D1
tSU:STA
tHD:STA
DATA(n)
DATA(1)
70%
70%
tSU:STO
D0
ACK
ACK
70%
tWR
tHIGH:WP
70%
30%
70%
30%
STOP CONDITION
START CONDITION
Figure 2-(b). Start-Stop Bit Timing
D0
write data
(n-th address)
ACK
70%
Figure 2-(e). WP Timing at Write Cancel
70%
70%
tWR
STOP CONDITION
START CONDITION
Figure 2-(c). Write Cycle Timing
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Datasheet
BR24T256-W
Block Diagram
A0
1
256Kbit EEPROM
Array
8
VCC
7
WP
6
SCL
5
SDA
8bit
A1
Address
Decoder
2
Word
Address Register
15bit
START
A2 3
Data
Register
STOP
Control Circuit
ACK
GND 4
High Voltage
Generating Circuit
Power Source
Voltage Detection
Figure 3. Block Diagram
Pin Configuration
(TOP VIEW)
A0
1
A1
2
8
VCC
7
WP
BR24T256-W
A2
3
6
SCL
GND
4
5
SDA
Pin Descriptions
Terminal
Name
Input/
Output
A0
Input
Slave address setting*
A1
Input
Slave address setting*
A2
Input
Slave address setting*
GND
SCL
Input/
Output
Input
WP
Input
VCC
-
SDA
Descriptions
Reference voltage of all input / output, 0V
Serial data input serial data output
Serial clock input
Write protect terminal
Connect the power source.
*A0, A1 and A2 are not allowed to use as open.
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Datasheet
BR24T256-W
Typical Performance Curves
(The following values are Typ)
6
6
Ta=-40 ℃
Ta= 25 ℃
Ta= 85 ℃
5
Input Low Voltage: VIL1(V)
Input High Voltage: VIH1(V)
5
4
3
SPEC
2
4
3
2
1
1
0
0
0
1
Ta=-40 ℃
Ta= 25℃
Ta= 85℃
2
3
4
5
SPEC
0
6
1
Supply Voltage: Vcc(V)
3
4
5
6
Figure 5. Input Low Voltage1,2 vs Supply Voltage
(A0, A1, A2, SCL, SDA, WP)
Figure 4. Input High Voltage1,2 vs Supply Voltage
(A0, A1, A2, SCL, SDA, WP)
1
1
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.8
Output Low Voltage2: VOL2(V)
Output Low Voltage1: VOL1(V)
2
Supply Voltage: Vcc(V)
0.6
SPEC
0.4
0.2
0
Ta=-40℃
Ta= 25 ℃
Ta= 85 ℃
0.8
0.6
0.4
SPEC
0.2
0
0
1
2
3
4
5
6
0
Output Low Current: IOL(mA)
2
3
4
5
6
Output Low Current: IOL(mA)
Figure 6. Output Low Voltage1 vs Output Low Current
(Vcc=2.5V)
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Figure 7. Output Low Voltage2 vs Output Low Current
(Vcc=1.6V)
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31.May.2013 Rev.003
Datasheet
BR24T256-W
Typical Performance Curves‐continued
1.2
1.2
Input Leakage Current: I LI (µA)
Output Leakage Current : I LO(µA)
SPEC
1
Ta=-40℃
Ta= 25 ℃
Ta= 85 ℃
0.8
0.6
0.4
0.2
SPEC
1
Ta=-40℃
Ta= 25 ℃
Ta= 85 ℃
0.8
0.6
0.4
0.2
0
0
0
1
2
3
4
5
0
6
1
3
4
5
6
Supply Voltage: Vcc(V)
Supply Voltage: Vcc(V)
Figure 8. Input Leakage Current vs Supply Voltage
(A0, A1, A2, SCL, WP)
Figure 9. Output Leakage Current vs Supply Voltage
(SDA)
0.6
3
SPEC
SPEC
2.5
Supply Current (Read): Icc2(mA)
Supply Current (Write): Icc1(mA)
2
2
Ta=-40 ℃
Ta= 25℃
Ta= 85℃
1.5
1
0.5
0
0.5
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.4
0.3
0.2
0.1
0
0
1
2
3
4
5
6
0
Supply Voltage: Vcc(V)
2
3
4
5
6
Supply Voltage: Vcc(V)
Figure 10. Supply Current (Write) vs Supply Voltage
(fscl=400kHz)
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Figure 11. Supply Current (Read) vs Supply Voltage
(fscl=400kHz)
TSZ02201-0R2R0G100140-1-2
31.May.2013 Rev.003
Datasheet
BR24T256-W
Typical Performance Curves‐continued
2.5
10000
SPEC
1000
Clock Frequency: fscl(kHz)
Standby Current : I SB (µA)
2
Ta=-40℃
Ta= 25℃
Ta= 85℃
1.5
1
0.5
SPEC
100
Ta=-40℃
Ta= 25℃
Ta= 85℃
10
1
0
0.1
0
1
2
3
4
5
6
0
1
Supply Voltage: Vcc(V)
3
4
5
6
Supply Voltage: Vcc(V)
Figure 13. Clock Frequency vs Supply Voltage
Figure 12. Standby Current vs Supply Voltage
1
LOW (µs)
1.5
0.8
SPEC
Data Clock Low Period : t
Data Clock High Period : t HIGH(µs)
2
0.6
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.4
0.2
0
SPEC
1.2
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.9
0.6
0.3
0
0
1
2
3
4
5
6
0
Supply Voltage: Vcc(V)
Figure 14. Data Clock High Period vs Supply Voltage
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1
2
3
4
Supply Voltage: Vcc(V)
5
6
Figure 15. Data Clock Low Period vs Supply Voltage
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Datasheet
BR24T256-W
Typical Performance Curves‐continued
1
Start Condition Setup Time: t SU:STA (µs)
Start Condition Hold Time: t HD:STA(µs)
1
0.8
SPEC
0.6
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.4
0.2
0
SPEC
0.6
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.4
0.2
0
-0.2
0
1
2
3
4
Supply Voltage: Vcc(V)
5
6
0
1
2
3
4
5
6
Supply Voltage: Vcc(V)
Figure 17. Start Condition Setup Time vs Supply Voltage
Figure 16. Start Condition Hold Time vs Supply Voltage
50
Input Data Hold Time: t HD:DAT(ns)
50
Input Data Hold Time: t HD:DAT (ns)
0.8
SPEC
0
-50
-100
Ta=-40℃
Ta= 25℃
Ta= 85℃
-150
SPEC
0
-50
Ta=-40℃
Ta= 25℃
Ta= 85℃
-100
-150
-200
-200
0
1
2
3
4
5
6
1
2
3
4
5
6
Supply Voltage: Vcc(V)
Supply Voltage: Vcc(V)
Figure 18. Input Data Hold Time vs Supply Voltage
(HIGH)
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Figure 19. Input Data Hold Time vs Supply Voltage
(LOW)
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31.May.2013 Rev.003
Datasheet
BR24T256-W
Typical Performance Curves‐continued
300
SU:DAT(ns)
200
SPEC
100
Input Data Setup Time: t
Input Data Setup Time: t SU:DAT(ns)
300
0
Ta=-40℃
Ta= 25℃
Ta= 85℃
-100
-200
200
SPEC
100
0
Ta=-40℃
Ta= 25℃
Ta= 85℃
-100
-200
0
1
2
3
4
5
6
0
1
Supply Voltage: Vcc(V)
4
5
6
Figure 21. Input Data Setup Time vs Supply Voltage
(LOW)
2
PD (µs)
2
Ta=-40℃
Ta= 25℃
Ta= 85℃
1.5
‘H’ Output Data Delay Time: t
PD(µs)
3
Supply Voltage: Vcc(V)
Figure 20. Input Data Setup Time vs Supply Voltage
(HIGH)
‘L’ Output Data Delay Time: t
2
SPEC
1
0.5
1.5
Ta=-40℃
Ta= 25℃
Ta= 85℃
SPEC
1
0.5
SPEC
SPEC
0
0
0
1
2
3
4
5
0
6
2
3
4
5
6
Supply Voltage: Vcc(V)
Supply Voltage: Vcc(V)
Figure 22. ‘L’ Output Data Delay Time vs Supply Voltage
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Figure 23. ‘H’ Output Data Delay Time vs Supply Voltage
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31.May.2013 Rev.003
Datasheet
BR24T256-W
Typical Performance Curves‐continued
2
1.5
BUF(µs)
Ta=-40℃
Ta= 25℃
Ta= 85℃
1
Bus Free Time : t
Stop Condition Setup Time: t
SU:STO(µs)
2
SPEC
0.5
1.5
SPEC
1
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.5
0
-0.5
0
0
1
2
3
4
5
6
0
1
2
Supply Voltage: Vcc(V)
Figure 24. Stop Condition Setup Time vs Supply Voltage
4
5
6
Figure 25. Bus Free Time vs Supply Voltage
0.6
6
SPEC
Noise Spike Width(SCL H):tI(µs)
5
Write Cycle Time: t WR(ms)
3
Supply Voltage: Vcc(V)
4
3
2
Ta=-40℃
Ta= 25℃
Ta= 85℃
1
0.5
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.4
0.3
0.2
0.1
SPEC
0
0
0
1
2
3
4
5
0
6
1
2
3
4
5
Supply Voltage: Vcc(V)
Supply Voltage: Vcc(V)
Figure 26. Write Cycle Time vs Supply Voltage
Figure 27. Noise Spike Width vs Supply Voltage
(SCL H)
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Datasheet
BR24T256-W
0.6
0.6
0.5
0.5
Noise Spike Width(SDA H): tI(µs)
Noise Spike Width(SCL L): tI(µs)
Typical Performance Curves‐continued
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.4
0.3
0.2
0.1
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.4
0.3
0.2
0.1
0
SPEC
0
0
1
2
3
4
5
6
0
1
2
Supply Voltage: Vcc(V)
3
4
5
6
Supply Voltage: Vcc(V)
Figure 29. Noise Spike Width vs Supply Voltage
(SDA H)
Figure 28. Noise Spike Width vs Supply Voltage
(SCL L)
0.6
1.2
0.5
1
HD:WP(µs)
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.4
WP Hold Time : t
Noise Spike Width(SDA L): tI(µs)
SPEC
0.3
0.2
0.1
0.8
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.6
0.4
0.2
SPEC
0
0
0
1
2
3
4
5
6
Supply Voltage: Vcc(V)
1
2
3
4
5
Supply Voltage: Vcc(V)
Figure 30. Noise Spike Width vs Supply Voltage
(SDA L)
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Figure 31. WP Hold Time vs Supply Voltage
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31.May.2013 Rev.003
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Datasheet
BR24T256-W
Typical Performance Curves‐continued
0.2
1.2
SPEC
0
SPEC
WP High Period: t HIGH:WP ( µs)
WP Setup Time: t
SU:WP(µs)
0.1
Ta=-40℃
Ta= 25℃
Ta= 85℃
-0.1
-0.2
-0.3
-0.4
1
0.8
Ta=-40℃
Ta= 25℃
Ta= 85℃
0.6
0.4
0.2
-0.5
0
-0.6
0
1
2
3
4
5
6
0
1
2
3
4
5
6
Supply Voltage: Vcc(V)
Supply Voltage: Vcc(V)
Figure 33. WP High Period vs Supply Voltage
Figure 32. WP Setup Time vs Supply Voltage
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Datasheet
BR24T256-W
Timing Chart
1. I2C BUS Data Communication
I2C BUS data communication starts by start condition input, and ends by stop condition input. Data is always 8bit long,
and acknowledge is always required after each byte. I2C BUS data communication with several devices is possible by
connecting with 2 communication lines: serial data (SDA) and serial clock (SCL).
Among the devices, there should be a “master” that generates clock and control communication start and end. The rest
become “slave” which are controlled by an address peculiar to each device, like this EEPROM. The device that outputs
data to the bus during data communication is called “transmitter”, and the device that receives data is called “receiver”..
SDA
1-7
SCL
S
START ADDRESS
condition
8
9
R/W
ACK
1-7
8
DATA
9
ACK
1-7
DATA
8
9
ACK
P
STOP
condition
Figure 34. Data Transfer Timing
2. Start Condition (Start Bit Recognition)
(1) Before executing each command, start condition (start bit) where SDA goes from 'HIGH' down to 'LOW' when SCL is
‘HIGH' is necessary.
(2) This IC always detects whether SDA and SCL are in start condition (start bit) or not, therefore, unless this condition
is satisfied, any command cannot be executed.
3. Stop Condition (Stop Bit Recognition)
(1) Each command can be ended by a stop condition (stop bit) where SDA goes from 'LOW' to 'HIGH' while SCL is
'HIGH'.
4. Acknowledge (ACK) Signal
(1) The acknowledge (ACK) signal is a software rule to show whether data transfer has been made normally or not. In a
master-slave communication, the device (Ex. µ-COM sends slave address input for write or read command, to this
IC ) at the transmitter (sending) side releases the bus after output of 8bit data.
(2) The device (Ex. This IC receives the slave address input for write or read command from the µ-COM) at the
receiver (receiving) side sets SDA 'LOW' during the 9th clock cycle, and outputs acknowledge signal (ACK signal)
showing that it has received the 8bit data.
(3) This IC, after recognizing start condition and slave address (8bit), outputs acknowledge signal (ACK signal) 'LOW'.
(4) After receiving 8bit data (word address and write data) during each write operation, this IC outputs acknowledge
signal (ACK signal) 'LOW'.
(5) During read operation, this IC outputs 8bit data (read data) and detects acknowledge signal (ACK signal) 'LOW'.
When acknowledge signal (ACK signal) is detected, and stop condition is not sent from the master (µ-COM) side,
this IC continues to output data. When acknowledge signal (ACK signal) is not detected, this IC stops data transfer,
recognizes stop condition (stop bit), and ends read operation. Then this IC becomes ready for another transmission.
5. Device Addressing
(1) Slave address comes after start condition from master.
(2) The significant 4 bits of slave address are used for recognizing a device type.
The device code of this IC is fixed to '1010'.
(3) Next slave addresses (A2 A1 A0 --- device address) are for selecting devices, and plural ones can be used on a
same bus according to the number of device addresses.
(4) The most insignificant bit ( R / W --- READ / WRITE ) of slave address is used for designating write or read operation,
and is as shown below.
Setting R / W to 0 ------- write (setting 0 to word address setting of random read)
Setting R / W to 1 ------- read
Maximum Number of
Connected Buses
Slave Address
1
0
1 0
A2
A1
A0
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Datasheet
BR24T256-W
Write Command
1. Write Cycle
(1) Arbitrary data can be written to this EEPROM. When writing only 1 byte, Byte Write is normally used, and when
writing continuous data of 2 bytes or more, simultaneous write is possible by Page Write cycle. The maximum
number of bytes is specified per device of each capacity. Up to 8 arbitrary bytes can be written.
S
T
A
R
T
SDA
LINE
W
R
I
T
E
SLAVE
ADDRESS
1st WORD
ADDRESS
1 0 1 0 A2 A1 A0
*
2nd WORD
ADDRESS
DATA
WA W A W AW A
14 13 12 11
WA
D7
0
A
C
K
R A
/ C
W K
S
T
O
P
D0
A
C
K
* Don't Care bit
A
C
K
Figure 35. Byte Write Cycle
S
T
A
R
T
SDA
LINE
SLAVE
ADDRESS
1 0 1
W
R
I
T
E
2nd WORD
ADDRESS(n)
1st WORD
ADDRESS(n)
WA WA WA WA
0 A2 A1 A0
*
14
DATA(n)
WA
D7
0
13 12 11
R A
/ C
W K
A
C
K
D0
A
C
K
S
T
O
P
DATA(n+63)
D0
A
C
K
* Don't Care bit
A
C
K
Figure 36. Page Write Cycle
(2)
(3)
(4)
(5)
(6)
During internal write execution, all input commands are ignored, therefore ACK is not returned.
Data is written to the address designated by word address (n-th address)
By issuing stop bit after 8bit data input, internal write to memory cell starts.
When internal write is started, command is not accepted for tWR (5ms at maximum).
Using page write cycle, writing in bulk is done as follows: When data of more than 64 bytes is sent, the bytes in
excess overwrite the data already send first.
(Refer to "Internal Address Increment")
(7) As for page write cycle of BR24T256-W, where 2 or more bytes of data is intended to be written, after the 9
significant bits of word address are designated arbitrarily, only the value of 6 least significant bits in the address is
incremented internally, so that data up to 64 bytes of memory only can be written.
In the case BR24T256-W, 1 page=64bytes, but the page write cycle time is 5ms at maximum for 64byte bulk write.
It does not stand 5ms at maximum × 64byte=320ms (Max).
2. Internal Address Increment
Page write mode (in the case of BR24T256-W)
3Eh
0
0
0
WA7
WA6
WA5
WA4
WA3
WA2
WA1
WA0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
0
0
1
1
0
1
1
0
1
1
0
1
1
0
1
1
0
0
1
0
Increment
For example, when it is started from address 3Eh,
then, increment is made as below,
3Eh→3Fh→00h→01h･･･ please take note.
※3Eh･･･3E in hexadecimal, therefore,
00111110 becomes a binary number.
Significant bit is fixed.
No digit up
3. Write Protect (WP) Terminal
Write Protect (WP) Function
When WP terminal is set at Vcc (H level), data rewrite of all addresses is prohibited. When it is set at GND (L level), data
rewrite of all address is enabled. Be sure to connect this terminal to Vcc or GND, or control it to H level or L level. Do not
leave it open.
In case of using it as ROM, it is recommended to connect it to pull up or Vcc.
At extremely low voltage at power ON / OFF, by setting the WP terminal 'H', write error can be prevented.
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Datasheet
BR24T256-W
Read Command
1. Read Cycle
Read cycle is when data of EEPROM is read. Read cycle could be random read cycle or current read cycle. Random
read cycle is a command to read data by designating a specific address, and is used generally. Current read cycle is a
command to read data of internal address register without designating an address, and is used when to verify just after
write cycle. In both the read cycles, sequential read cycle is available where the next address data can be read in
succession.
S
T
A
R
T
SDA
LINE
SLAVE
ADDRESS
1 0
W
R
I
T
E
1st WORD
ADDRESS(n)
2nd WORD
ADDRESS(n)
R
E
A
D
SLAVE
ADDRESS
S
T
O
P
DATA(n)
WA
WAWAWAWA
1 0 A2 A1 A0
S
T
A
R
T
10 1 0
0
* 14 13 12 11
R A
/ C
W K
A
C
K
A2 A1A0
A
C
K
D7
D0
R A
/ C
W K
* Don’t Care bit
A
C
K
Figure 37. Random Read Cycle
S
T
A
R
T
SDA
LINE
R
E
A
D
SLAVE
ADDRESS
1 0 1 0 A2A1A0
S
T
O
P
DATA(n)
D7
D0
A
C
K
R A
/ C
WK
Figure 38. Current Read Cycle
S
T
A
R
T
SDA
LINE
SLAVE
ADDRESS
R
E
A
D
1 0 1 0 A2 A1A0
DATA(n)
D7
R A
/ C
WK
S
T
O
P
DATA(n+x)
D0
D7
A
C
K
A
C
K
D0
A
C
K
Figure 39. Sequential Read Cycle (in the case of current read cycle)
(1) In random read cycle, data of designated word address can be read.
(2) When the command just before current read cycle is random read cycle, current read cycle (each including
sequential read cycle), data of incremented last read address (n)-th, i.e., data of the (n+1)-th address is output.
(3) When ACK signal 'LOW' after D0 is detected, and stop condition is not sent from master (µ-COM) side, the next
address data can be read in succession.
(4) Read cycle is ended by stop condition where 'H' is input to ACK signal after D0 and SDA signal goes from ‘L’ to ‘H’
while SCL signal is 'H'.
(5) When 'H' is not input to ACK signal after D0, sequential read gets in, and the next data is output.
Therefore, read command cycle cannot be ended. To end read command cycle, be sure to input 'H' to ACK signal
after D0, and the stop condition where SDA goes from ‘L’ to ‘H’ while SCL signal is 'H'.
(6) Sequential read is ended by stop condition where 'H' is input to ACK signal after arbitrary D0 and SDA is asserted
from ‘L’ to ‘H’ while SCL signal is 'H'.
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Datasheet
BR24T256-W
Software Reset
Software reset is executed to avoid malfunction after power on and during command input. Software reset has several
kinds and 3 kinds of them are shown in the figure below. (Refer to Figure 40-(a), Figure 40-(b), and Figure 40-(c).) Within
the dummy clock input area, the SDA bus is released ('H' by pull up) and ACK output and read data '0' (both 'L' level) may
be output from EEPROM. Therefore, if 'H' is input forcibly, output may conflict and over current may flow, leading to
instantaneous power failure of system power source or influence upon devices.
Dummy clock×14
SCL
1
2
Start×2
13
Normal command
14
SDA
Normal command
Figure 40-(a). The Case of Dummy Clock×14 + START+START+ Command Input
SCL
Start
Dummy clock×9
Start
1
2
8
Normal command
9
SDA
Normal command
Figure 40-(b). The Case of START + Dummy Clock×9 + START + Command Input
Start×9
SCL
1
2
3
7
8
Normal command
9
SDA
Normal command
SD
Figure 40-(c). START×9 + Command Input
※Start command from START input.
Acknowledge Polling
During internal write execution, all input commands are ignored, therefore ACK is not returned. During internal automatic
write execution after write cycle input, next command (slave address) is sent. If the first ACK signal sends back 'L', then it
means end of write operation, else 'H' is returned, which means writing is still in progress. By the use of acknowledge
polling, next command can be executed without waiting for tWR = 5ms.
To write continuously, R / W = 0, then to carry out current read cycle after write, slave address with R / W = 1 is sent. If
ACK signal sends back 'L', and then execute word address input and data output and so forth..
During internal write,
ACK = HIGH is returned.
First write command
S
T
A
R
T
Write command
S
T
O
P
S
T Slave
A
R address
T
S
T Slave
A
R address
T
A
C
K
H
A
C
K
H
…
tWR
Second write command
…
S
T Slave
A
R address
T
A
C
K
H
S
T Slave
A
R address
T
A
C
K
L
Word
address
A
C
K
L
Data
A
C
K
L
S
T
O
P
tWR
After completion of internal write,
ACK=LOW is returned, so input next
word address and data in succession.
Figure 41. Case of Continuous Write by Acknowledge Polling
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Datasheet
BR24T256-W
WP Valid Timing (Write Cancel)
WP is usually fixed to 'H' or 'L', but when WP is used to cancel write cycle and so on, observe the following WP valid timing.
During write cycle execution, inside cancel valid area, by setting WP='H', write cycle can be cancelled. In both byte write
cycle and page write cycle, the area from the first start condition of command to the rise of clock to take in D0 of data(in
page write cycle, the first byte data) is the cancel invalid area.
WP input in this area becomes ‘Don't care’. The area from the rise of SCL to take in D0 to the stop condition input is the
cancel valid area. Furthermore, after the execution of forced end by WP, the IC enters standby status.
・Rise of SDA
・Rise of D0 taken clock
SCL
SDA
SCL
D1
D0
ACK
SDA
Enlarged view
SDA
S
T Slave
A
R address
T
A
C Word
K address
L
D0
ACK
Enlarged view
A
C D7 D6 D5 D4 D3 D2 D1 D0
K
L
WP cancel invalid area
A
C
K
L
Data
A
C
K
L
S
T
O
P
WP cancel valid area
tWR
WP cancel invalid area
WP
Data is not written.
Figure 42. WP Valid Timing
Command Cancel by Start Condition and Stop Condition
During command input, by continuously inputting start condition and stop condition, command can be cancelled. (Figure
43.) However, within ACK output area and during data read, SDA bus may output 'L'. In this case, start condition and stop
condition cannot be input, so reset is not available. Therefore, execute software reset. When command is cancelled by
start-stop condition during random read cycle, sequential read cycle, or current read cycle, internal setting address is not
determined. Therefore, it is not possible to carry out current read cycle in succession. To carry out read cycle in succession,
carry out random read cycle.
SCL
SDA
1
0
1
0
Start condition
Stop condition
Figure 43. Case of Cancel by Start, Stop Condition during Slave Address Input
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Datasheet
BR24T256-W
I/O Peripheral Circuit
1. Pull-up Resistance of SDA Terminal
SDA is NMOS open drain, so it requires a pull up resistor. As for this resistance value (RPU), select an appropriate value
from microcontroller VIL, IL, and VOL-IOL characteristics of this IC. If RPU is large, operating frequency is limited. The smaller
the RPU, the larger is the supply current (Read).
2. Maximum Value of RPU
The maximum value of RPU is determined by the following factors.
(1) SDA rise time to be determined by the capacitance (CBUS) of bus line and RPU of SDA should be tR or lower.
Furthermore, AC timing should be satisfied even when SDA rise time is slow.
(2) The bus. electric potential ○
A to be determined by the input current leak total (IL) of device connected to bus at
output of 'H' to the SDA line and RPU should sufficiently secure the input 'H' level (VIH) of microcontroller and
EEPROM including recommended noise margin of 0.2Vcc.
VCC-ILRPU-0.2 VCC ≧ VIH
∴ RPU≦
0.8Vcc－VIH
IL
Microcontroller
BR24TXX
RPU
Ex.) Vcc =3V IL=10µA VIH=0.7 Vcc
From (2)
0.8×3－0.7×3
RPU≦
10×10-6
SDA terminal
A
IL
≦ 30 [kΩ]
IL
Bus line
capacity
CBUS
Figure 44. I/O circuit diagram
3. Minimum Value of RPU
The minimum value of RPU is determined by the following factors.
(1) When IC outputs LOW, it should be satisfied that VOLMAX=0.4V and IOLMAX=3mA.
Vcc－VOL
≦IOL
RPU
Vcc－VOL
∴ RPU≧
IOL
(2) VOLMAX=0.4V should secure the input 'L' level (VIL) of microcontroller and EEPROM including recommended noise
margin 0.1Vcc.
VOLMAX ≦ VIL-0.1 VCC
Ex.) VCC =3V, VOL=0.4V, IOL=3mA, microcontroller, EEPROM VIL=0.3Vcc
from (1)
3－0.4
RPU≧
3×10－3
≧ 867 [Ω]
And
VOL=0.4 [V]
VIL=0.3×3
=0.9 [V]
Therefore, the condition (2) is satisfied.
4. Pull-up Resistance of SCL Terminal
When SCL control is made at the CMOS output port, there is no need for a pull up resistor. But when there is a time
where SCL becomes 'Hi-Z', add a pull up resistor. As for the pull up resistor value, one of several kΩ to several ten kΩ is
recommended in consideration of drive performance of output port of microcontroller.
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Datasheet
BR24T256-W
Cautions on Microcontroller Connection
1. RS
In I2C BUS, it is recommended that SDA port is of open drain input/output. However, when using CMOS input / output of
tri state to SDA port, insert a series resistance RS between the pull up resistor RPU and the SDA terminal of EEPROM.
This is to control over current that may occur when PMOS of the microcontroller and NMOS of EEPROM are turned ON
simultaneously. RS also plays the role of protecting the SDA terminal against surge. Therefore, even when SDA port is
open drain input/output, RS can be used.
ACK
SCL
RPU
RS
SDA
'H' output of microcontroller
'L' output of EEPROM
Microcontroller
EEPROM
Over current flows to SDA line by 'H'
output of microcontroller and 'L'
output of EEPROM.
Figure 45. I/O Circuit Diagram
Figure 46. Input / Output Collision Timing
2. Maximum Value of RS
The maximum value of RS is determined by the following relations.
(1) SDA rise time to be determined by the capacitance (CBUS) of bus line and RPU of SDA should be tR or lower.
Furthermore, AC timing should be satisfied even when SDA rise time is slow.
(2) The bus’ electric potential ○
A to be determined by RPU and RS the moment when EEPROM outputs 'L' to SDA bus
should sufficiently secure the input 'L' level (VIL) of microcontroller including recommended noise margin of 0.1Vcc.
(Vcc－VOL)×RS
+VOL+0.1Vcc≦VIL
RPU+RS
VCC
RPU A
RS
∴ RS≦
VOL
IOL
Ex)VCC=3V VIL=0.3VCC VOL=0.4V RPU=20kΩ
Bus line
capacity
CBUS
VIL
VIL－VOL－0.1Vcc
×RPU
1.1Vcc－VIL
RS≦
0.3×3－0.4－0.1×3
×20×103
1.1×3－0.3×3
EEPROM
Micro controller
≦1.67 [kΩ]
Figure 47. I/O Circuit Diagram
3. Minimum Value of RS
The minimum value of RS is determined by over current at bus collision. When over current flows, noises in power source
line and instantaneous power failure of power source may occur. When allowable over current is defined as I, the
following relation must be satisfied. Determine the allowable current in consideration of the impedance of power source
line in set and so forth. Set the over current to EEPROM at 10mA or lower.
Vcc
RS ≦I
RPU
'L'output
∴ RS≧
RS
Vcc
I
EX) VCC=3V I=10mA
Over current I
RS≧
'H' output
3
3
10×10－
≧300 [Ω]
Microcontroller
EEPROM
Figure 48. I/O Circuit Diagram
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BR24T256-W
I/O Equivalence Circuit
1. Input (A0, A1, A2, SCL, WP)
Figure 49. Input Pin Circuit Diagram
2. Input / Output (SDA)
Figure 50. Input / Output Pin Circuit Diagram
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Power-Up / Down Conditions
At power ON, the IC’s internal circuits may go through unstable low voltage area as the Vcc rises, making the IC’s internal
logic circuit not completely reset, hence, malfunction may occur. To prevent this, the IC is equipped with POR circuit and
LVCC circuit. To assure the operation, observe the following conditions at power ON.
1. Set SDA = 'H' and SCL ='L' or 'H’
2. Start power source so as to satisfy the recommended conditions of tR, tOFF, and Vbot for operating POR circuit.
tR
Recommended conditions of tR, tOFF,Vbot
VCC
tR
tOFF
Vbot
0
tOFF
Vbot
10ms or below
10ms or larger
0.3V or below
100ms or below
10ms or larger
0.2V or below
Figure 51. Rise Waveform Diagram
3. Set SDA and SCL so as not to become 'Hi-Z'.
When the above conditions 1 and 2 cannot be observed, take the following countermeasures.
(1) In the case when the above condition 1 cannot be observed such that SDA becomes 'L' at power ON.
→Control SCL and SDA as shown below, to make SCL and SDA, 'H' and 'H'.
VCC
tLOW
SCL
SDA
After Vcc becomes stable
After Vcc becomes stable
tDH
tSU:DAT
Figure 52. When SCL= 'H' and SDA= 'L'
tSU:DAT
Figure 53. When SCL='L' and SDA='L'
(2) In the case when the above condition 2 cannot be observed.
→After power source becomes stable, execute software reset (Page 16).
(3) In the case when the above conditions 1 and 2 cannot be observed.
→Carry out (1), and then carry out (2).
Low Voltage Malfunction Prevention Function
LVCC circuit prevents data rewrite operation at low power, and prevents write error. At LVCC voltage (Typ =1.2V) or below,
data rewrite is prevented.
Noise Countermeasures
1. Bypass Capacitor
When noise or surge gets in the power source line, malfunction may occur, therefore, it is recommended to connect a
bypass capacitor (0.1µF) between IC Vcc and GND pins. Connect the capacitor as close to IC as possible. In addition, it
is also recommended to connect a bypass capacitor between board’s Vcc and GND.
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BR24T256-W
Operational Notes
1.
Described numeric values and data are design representative values only, and the values are not guaranteed.
2.
We believe that the application circuit examples in this document are recommendable. However, in actual use, confirm
characteristics further sufficiently. If changing the fixed number of external parts is desired, make your decision with
sufficient margin in consideration of static characteristics, transient characteristics, and fluctuations of external parts
and our LSI.
3.
Absolute maximum ratings
If the absolute maximum ratings such as supply voltage, operating temperature range, and so on are exceeded, LSI
may be destroyed. Do not supply voltage or subject the IC to temperatures exceeding the absolute maximum ratings.
In the case of fear of exceeding the absolute maximum ratings, take physical safety countermeasures such as adding
fuses, and see to it that conditions exceeding the absolute maximum ratings should not be supplied to the LSI.
4.
GND electric potential
Set the voltage of GND terminal lowest at any operating condition. Make sure that each terminal voltage is not lower
than that of GND terminal.
5.
Thermal design
Use a thermal design that allows for a sufficient margin by taking into account the permissible power dissipation (Pd) in
actual operating conditions.
6.
Short between pins and mounting errors
Be careful when mounting the IC on printed circuit boards. The IC may be damaged if it is mounted in a wrong
orientation or if pins are shorted together. Short circuit may be caused by conductive particles caught between the pins.
7.
Operating the IC in the presence of strong electromagnetic field may cause malfunction, therefore, evaluate design
sufficiently.
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Datasheet
BR24T256-W
Part Numbering
B
R
2 4
T
2 5 6
x
x
x
-
W
x
x
BUS Type
24：I2C
Operating Temperature/
Power Source Voltage
-40℃ to +85℃/
1.6V to 5.5V
Capacity
256=256K
Package
Blank
:DIP-T8
F
:SOP8
FJ
:SOP-J8
FV
: SSOP-B8
FVT
: TSSOP-B8
Double Cell
Packaging and Forming Specification
E2
: Embossed tape and reel
(SOP8,SOP-J8, SSOP-B8,TSSOP-B8)
None : Tube
(DIP-T8)
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Datasheet
BR24T256-W
Physical Dimensions Tape and Reel Information
DIP-T8
9.3±0.3
5
1
4
3.2±0.2 3.4±0.3
0.51Min.
6.5±0.3
8
7.62
0.3±0.1
0°−15°
2.54
0.5±0.1
(Unit : mm)
<Tape and Reel information>
Container
Tube
Quantity
2000pcs
Direction of feed
Direction of products is fixed in a container tube
∗ Order quantity needs to be multiple of the minimum quantity.
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TSZ02201-0R2R0G100140-1-2
31.May.2013 Rev.003
Datasheet
BR24T256-W
SOP8
6
5
1 2
3
4
0.3MIN
7
4.4±0.2
6.2±0.3
8
+6°
4° −4°
0.9±0.15
5.0±0.2
(MAX 5.35 include BURR)
0.595
1.5±0.1
+0.1
0.17 -0.05
S
S
0.11
0.1
1.27
0.42±0.1
(Unit : mm)
<Tape and Reel information>
Tape
Embossed carrier tape
Quantity
2500pcs
Direction
of feed
E2
The direction is the 1pin of product is at the upper left when you hold
( reel on the left hand and you pull out the tape on the right hand
Direction of feed
1pin
Reel
www.rohm.com
©2013 ROHM Co., Ltd. All rights reserved.
TSZ22111･15･001
)
∗ Order quantity needs to be multiple of the minimum quantity.
25/30
TSZ02201-0R2R0G100140-1-2
31.May.2013 Rev.003
Datasheet
BR24T256-W
SOP-J8
4.9±0.2
(MAX 5.25 include BURR)
7
6
5
1
2
3
4
0.45MIN
8
3.9±0.2
6.0±0.3
+6°
4° −4°
0.545
0.2±0.1
1.375±0.1
S
0.175
1.27
0.42±0.1
0.1 S
(Unit : mm)
<Tape and Reel information>
Tape
Embossed carrier tape
Quantity
2500pcs
Direction
of feed
E2
The direction is the 1pin of product is at the upper left when you hold
( reel on the left hand and you pull out the tape on the right hand
Direction of feed
1pin
Reel
www.rohm.com
©2013 ROHM Co., Ltd. All rights reserved.
TSZ22111･15･001
)
∗ Order quantity needs to be multiple of the minimum quantity.
26/30
TSZ02201-0R2R0G100140-1-2
31.May.2013 Rev.003
Datasheet
BR24T256-W
SSOP-B8
3.0±0.2
(MAX 3.35 include BURR)
7
6
5
1
2
3
4
0.1
1.15±0.1
0.3MIN
6.4 ± 0.3
4.4 ± 0.2
8
0.15±0.1
S
(0.52)
0.65
0.1 S
+0.06
0.22 −0.04
0.08
M
(Unit : mm)
<Tape and Reel information>
Tape
Embossed carrier tape
Quantity
2500pcs
Direction
of feed
E2
The direction is the 1pin of product is at the upper left when you hold
( reel on the left hand and you pull out the tape on the right hand
Direction of feed
1pin
Reel
www.rohm.com
©2013 ROHM Co., Ltd. All rights reserved.
TSZ22111･15･001
)
∗ Order quantity needs to be multiple of the minimum quantity.
27/30
TSZ02201-0R2R0G100140-1-2
31.May.2013 Rev.003
Datasheet
BR24T256-W
TSSOP-B8
3.0 ± 0.1
(MAX 3.35 include BURR)
7
6
5
1
2
3
4
4±4
1.0±0.2
0.5±0.15
1PIN MARK
0.525
+0.05
0.145 −0.03
S
0.1±0.05
1.2MAX
1.0±0.05
6.4±0.2
4.4±0.1
8
0.08 S
+0.05
0.245 −0.04
0.08
M
0.65
(Unit : mm)
<Tape and Reel information>
Tape
Embossed carrier tape
Quantity
3000pcs
Direction
of feed
E2
The direction is the 1pin of product is at the upper left when you hold
( reel on the left hand and you pull out the tape on the right hand
Direction of feed
1pin
Reel
www.rohm.com
©2013 ROHM Co., Ltd. All rights reserved.
TSZ22111･15･001
)
∗ Order quantity needs to be multiple of the minimum quantity.
28/30
TSZ02201-0R2R0G100140-1-2
31.May.2013 Rev.003
Datasheet
BR24T256-W
Marking Diagrams (TOP VIEW)
SOP8 (TOP VIEW)
DIP-T8 (TOP VIEW)
Part Number Marking
Part Number Marking
BR24T256
4T256
LOT Number
LOT Number
1PIN MARK
SOP-J8 (TOP VIEW)
SSOP-B8 (TOP VIEW)
Part Number Marking
Part Number Marking
T256
4T256
LOT Number
LOT Number
4
1PIN MARK
1PIN MARK
TSSOP-B8 (TOP VIEW)
4T256
Part Number Marking
LOT Number
1PIN MARK
www.rohm.com
©2013 ROHM Co., Ltd. All rights reserved.
TSZ22111･15･001
29/30
TSZ02201-0R2R0G100140-1-2
31.May.2013 Rev.003
Datasheet
BR24T256-W
Revision History
Date
Revision
18.May.2012
001
25.Feb.2013
002
31.May.2013
003
www.rohm.com
©2013 ROHM Co., Ltd. All rights reserved.
TSZ22111･15･001
Changes
New Release
Update some English words, sentences’ descriptions, grammar and formatting.
Add tF2 in Serial Input / Output Timing
P1 Change format of package line-up table.
P.2 Add VESD in Absolute Maximum Ratings
P.4 Add directions in Pin Descriptions
30/30
TSZ02201-0R2R0G100140-1-2
31.May.2013 Rev.003
Datasheet
Notice
Precaution on using ROHM Products
1.
Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
(Note 1)
, transport
intend to use our Products in devices requiring extremely high reliability (such as medical equipment
equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car
accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or
serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.
Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any
damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific
Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASSⅢ
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅣ
CLASSⅢ
2.
ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate
safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which
a failure or malfunction of our Products may cause. The following are examples of safety measures:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure
3.
Our Products are designed and manufactured for use under standard conditions and not under any special or
extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way
responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any
special or extraordinary environments or conditions. If you intend to use our Products under any special or
extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of
product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of
flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Products in places subject to dew condensation
4.
The Products are not subject to radiation-proof design.
5.
Please verify and confirm characteristics of the final or mounted products in using the Products.
6.
In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7.
De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual
ambient temperature.
8.
Confirm that operation temperature is within the specified range described in the product specification.
9.
ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1.
When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2.
In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the
ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice - GE
© 2014 ROHM Co., Ltd. All rights reserved.
Rev.002
Datasheet
Precautions Regarding Application Examples and External Circuits
1.
If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2.
You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses
incurred by you or third parties arising from the use of such information.
Precaution for Electrostatic
This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper
caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be
applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron,
isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control).
Precaution for Storage / Transportation
1.
Product performance and soldered connections may deteriorate if the Products are stored in the places where:
[a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2
[b] the temperature or humidity exceeds those recommended by ROHM
[c] the Products are exposed to direct sunshine or condensation
[d] the Products are exposed to high Electrostatic
2.
Even under ROHM recommended storage condition, solderability of products out of recommended storage time period
may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is
exceeding the recommended storage time period.
3.
Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads
may occur due to excessive stress applied when dropping of a carton.
4.
Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of
which storage time is exceeding the recommended storage time period.
Precaution for Product Label
QR code printed on ROHM Products label is for ROHM’s internal use only.
Precaution for Disposition
When disposing Products please dispose them properly using an authorized industry waste company.
Precaution for Foreign Exchange and Foreign Trade act
Since our Products might fall under controlled goods prescribed by the applicable foreign exchange and foreign trade act,
please consult with ROHM representative in case of export.
Precaution Regarding Intellectual Property Rights
1.
All information and data including but not limited to application example contained in this document is for reference
only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any
other rights of any third party regarding such information or data. ROHM shall not be in any way responsible or liable
for infringement of any intellectual property rights or other damages arising from use of such information or data.:
2.
No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any
third parties with respect to the information contained in this document.
Other Precaution
1.
This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.
2.
The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written
consent of ROHM.
3.
In no event shall you use in any way whatsoever the Products and the related technical information contained in the
Products or this document for any military purposes, including but not limited to, the development of mass-destruction
weapons.
4.
The proper names of companies or products described in this document are trademarks or registered trademarks of
ROHM, its affiliated companies or third parties.
Notice - GE
© 2014 ROHM Co., Ltd. All rights reserved.
Rev.002
Datasheet
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3.
The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or
concerning such information.
Notice – WE
© 2014 ROHM Co., Ltd. All rights reserved.
Rev.001
Datasheet
BR24T256-W - Web Page
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Distribution Inventory
Part Number
Package
Unit Quantity
Minimum Package Quantity
Packing Type
Constitution Materials List
RoHS
BR24T256-W
DIP-T8
2000
50
Tube
inquiry
Yes