Product structure : Silicon monolithic integrated circuit This product has no designed protection against radioactive rays
1/31
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 14 001
www.rohm.com
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
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
WP (Write Protect) Function added
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
Packages W(Typ) x D(Typ) x H(Max)
BR24T256-W
Capacity
Bit Format
Type
Power Source
Voltage
256Kbit
32K×8
BR24T256-W
1.6V to 5.5V
BR24T256-WZ
BR24T256F-W
BR24T256FJ-W
BR24T256FV-W
BR24T256FVT-W
(1) Not Recommended for New Designs. Recommend BR24T256-WZ.
Figure 1.
SOP8
5.00mm x 6.20mm x 1.71mm
SOP- J8
4.90mm x 6.00mm x 1.65mm
SSOP-B8
3.00mm x 6.40mm x 1.35mm
TSSOP-B8
3.00mm x 6.40mm x 1.20mm
DIP-T8
9.30mm x 6.50mm x 7.10mm
DIP8K
9.27mm x 6.35mm x 8.63mm
Datashee
t
Datasheet
2/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Absolute Maximum Ratings (Ta=25ºC)
Parameter
Symbol
Rating
Unit
Remark
Supply Voltage
Vcc
-0.3 to +6.5
V
Power Dissipation
Pd
450 (SOP8)
mW
Derate by 4.5mWC when operating above Ta=25°C
450 (SOP-J8)
Derate by 4.5mWC when operating above Ta=25°C
300 (SSOP-B8)
Derate by 3.0mWC when operating above Ta=25°C
330 (TSSOP-B8)
Derate by 3.3mWC when operating above Ta=25°C.
800 (DIP-T8 (1))
Derate by 8.0mW/°C when operating above Ta=25°C
852 (DIP8K)
Derate by 8.52mW/°C when operating above Ta=25°C
When mounted (on 114.5 mm × 101.5 mm × 1.6 mm thick, glass
epoxy on single-layer substrate).
Storage Temperature
Tstg
-65 to +150
°C
Operating Temperature
Topr
-40 to +85
°C
Input Voltage /
Output Voltage
-
-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.
Junction
Temperature
Tjmax
150
°C
Junction temperature at the storage condition
Electrostatic discharge
voltage
(human body model)
VESD
-4000 to +4000
V
(1) Not Recommended for New Designs. Recommend BR24T256-WZ.
Memory Cell Characteristics (Ta=25ºC, Vcc=1.6V to 5.5V)
Parameter
Limit
Unit
Min
Typ
Max
Write Cycles (1)
1,000,000
-
-
Times
Data Retention (1)
40
-
-
Years
(1) Not 100% TESTED
Recommended Operating Ratings
Parameter
Symbol
Rating
Unit
Power Source Voltage
Vcc
1.6 to 5.5
V
Input Voltage
VIN
0 to Vcc
DC Characteristics
(
Unless otherwise specified, Ta=-40ºC to +85ºC
,
Vcc=1.6V to 5.5V
)
Parameter
Symbol
Limit
Unit
Conditions
Min
Typ
Max
Input High Voltage1
VIH1
0.7Vcc
-
Vcc+1.0
V
1.7VVcc5.5V
Input Low Voltage1
VIL1
-0.3(2)
-
+0.3Vcc
V
1.7VVcc5.5V
Input High Voltage2
VIH2
0.8Vcc
-
Vcc+1.0
V
1.6VVcc<1.7V
Input Low Voltage2
VIL2
-0.3(2)
-
+0.2Vcc
V
1.6VVcc<1.7V
Output Low Voltage1
VOL1
-
-
0.4
V
IOL=3.0mA, 2.5VVcc5.5V (SDA)
Output Low Voltage2
VOL2
-
-
0.2
V
IOL=0.7mA, 1.6VVcc<2.5V (SDA)
Input Leakage Current
ILI
-1
-
+1
µA
VIN=0 to Vcc
Output Leakage Current
ILO
-1
-
+1
µA
VOUT=0 to Vcc (SDA)
Supply Current (Write)
ICC1
-
-
2.5
mA
Vcc=5.5V, fSCL=400kHz, tWR=5ms,
Byte write, Page write
Supply Current (Read)
ICC2
-
-
0.5
mA
Vcc=5.5V, fSCL=400kHz
Random read, current read, sequential read
Standby Current
ISB
-
-
2.0
µA
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.
Datasheet
3/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
AC Characteristics
(Unless otherwise specified, Ta=-40ºC to +85ºC, Vcc=1.6V to 5.5V)
Parameter
Symbol
Limit
Unit
Min
Typ
Max
Clock Frequency
fSCL
-
-
400
kHz
Data Clock High Period
tHIGH
0.6
-
-
µs
Data Clock Low Period
tLOW
1.2
-
-
µs
SDA,SCL(INPUT) Rise Time (1)
tR
-
-
1.0
µs
SDA,SCL (INPUT)Fall Time (1)
tF1
-
-
1.0
µs
SDA(OUTPUT)Fall Time (1)
tF2
-
-
0.3
µs
Start Condition Hold Time
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
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
Noise Spike Width (SDA and SCL)
tI
-
-
0.1
µs
WP Hold Time
tHD:WP
1.0
-
-
µs
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
SCL
SDA
(入力)
SDA
(出力)
tR
tF1
tHIGH
tSU:DAT
tLOW
tHD:DAT
tDH
tPD
tBUF
tHD:STA
70%
30%
70%
70%
30%
70%
70%
30%
30%
70%
70%
30%
70%
70%
70%
70%
30%
30%
30%
30%
tF2
(INPUT)
(OUTPUT)
Input read at the rise edge of SCL
Data output in sync with the fall of SCL
Figure 2-(a). Serial Input / Output Timing
Figure 2-(b). Start-Stop Bit Timing
Figure 2-(c). Write Cycle Timing
Figure 2-(d). WP Timing at Write Execution
Figure 2-(e). WP Timing at Write Cancel
SDA
(output)
70%70%
70%
70%
tSU:STA
tHD:STA
START CONDITION
tSU:STO
STOP CONDITION
30%
30%
70%
30%
30%
70%
START CONDITION
STOP CONDITION
30%
30%
D0
ACK
tWR
write data
(n-th address)
START CONDITION
STOP CONDITION
70%
70%
DATA(1)
D0
ACK
D1
DATA(n)
ACK
tWR
30%
70%
STOP CONDITION
tHD:WP
tSU:WP
30%
DATA(1)
D0
D1 ACK
DATA(n)
ACK
tHIGH:WP
70%
70%
tWR
70%
70%
Fig1-(4) Write cycle timing
Fig1-(5) WP timing at write execution
Fig1-(6) WP timing at write cancel
STOP CONDITION
tHD:WP
tSU:WP
DATA(1)
D0
D1 ACK
DATA(n)
ACK
tHIGH:WP
70%
70%
tWR
70%
Fig1-(5) WP timing at write execution
Fig1-(6) WP timing at write cancel
Datasheet
4/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Block Diagram
Figure 3. Block Diagram
Pin Configuration
(TOP VIEW)
Pin Descriptions
Terminal
Name
Input/
Output
Descriptions
A0
Input
Slave address setting*
A1
Input
Slave address setting*
A2
Input
Slave address setting*
GND
-
Reference voltage of all input / output, 0V
SDA
Input/
Output
Serial data input serial data output
SCL
Input
Serial clock input
WP
Input
Write protect terminal
VCC
-
Connect the power source.
*A0, A1 and A2 are not allowed to use as open.
8
7
6
5
4
3
2
1
SDA
SCL
WP
V
CC
GND
A2
A1
A0
Address
Decoder
Word
Address
Register
Data
Register
Control Circuit
High Voltage
Generating Circuit
Power Source
Voltage Detection
8bit
ACK
START
STOP
15bit
256Kbit EEPROM Array
2
5
6
VCC
SCL
GND
BR24T256-W
1
3
4
7
8
WP
SDA
A2
A1
A0
Datasheet
5/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Figure 6. Output Low Voltage1 vs Output Low Current
(Vcc=2.5V)
Figure 7. Output Low Voltage2 vs Output Low Current
(Vcc=1.6V)
Figure 4. Input High Voltage1,2 vs Supply Voltage
(A0, A1, A2, SCL, SDA, WP)
Figure 5. Input Low Voltage1,2 vs Supply Voltage
(A0, A1, A2, SCL, SDA, WP)
Typical Performance Curves
(The following values are Typ)
0
0.2
0.4
0.6
0.8
1
0123456
Output Low Voltage1: VOL1(V)
Output Low Current: IOL(mA)
SPEC
Ta=-40
Ta= 25
Ta= 85
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0 1 2 3 4 5 6
Input Low Voltage:VIL1 ( V)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.2
0.4
0.6
0.8
1
1.2
0 1 2 3 4 5 6
Input High Voltage:VIH1 ( V)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.2
0.4
0.6
0.8
1
0123456
Output Low Voltage2: VOL2(V)
Output Low Current: IOL(mA)
Ta=-40
Ta= 25
Ta= 85
SPEC
Datasheet
6/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Figure 11. Supply Current (Read) vs Supply Voltage
(fscl=400kHz)
Figure 8. Input Leakage Current vs Supply
Voltage
(A0, A1, A2, SCL, WP)
Figure 9. Output Leakage Current vs Supply Voltage
(SDA)
Figure 10. Supply Current (Write) vs Supply Voltage
(fscl=400kHz)
Typical Performance Curves - continued
0
0.2
0.4
0.6
0.8
1
1.2
0 1 2 3 4 5 6
Input Leakage Current: I LI (µA)
Supply Voltage: Vcc(V)
Ta=-40
Ta= 25
Ta= 85
SPEC
0
0.2
0.4
0.6
0.8
1
1.2
0123456
Output Leakage Current : I LO(µA)
Supply Voltage: Vcc(V)
Ta=-40
Ta= 25
Ta= 85
SPEC
0
0.1
0.2
0.3
0.4
0.5
0.6
0123456
Supply Current (Read): Icc2(mA)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.5
1
1.5
2
2.5
3
0 1 2 3 4 5 6
Supply Current (Write): Icc1(mA)
Supply Voltage: Vcc(V)
Ta=-40
Ta= 25
Ta= 85
SPEC
Datasheet
7/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Figure 13. Clock Frequency vs Supply Voltage
Figure 14. Data Clock High Period vs Supply Voltage
Figure 12. Standby Current vs Supply Voltage
Figure 15. Data Clock Low Period vs Supply Voltage
Typical Performance Curves - continued
0.1
1
10
100
1000
10000
0 1 2 3 4 5 6
Clock Frequency: fscl(kHz)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.5
1
1.5
2
2.5
0 1 2 3 4 5 6
Standby Current : I SB (µA)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.2
0.4
0.6
0.8
1
0 1 2 3 4 5 6
Data Clock High Period : t HIGH(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.3
0.6
0.9
1.2
1.5
0123456
Data Clock Low Period : t LOW(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
Datasheet
8/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Figure 17. Start Condition Setup Time vs Supply Voltage
Figure 18. Input Data Hold Time vs Supply Voltage
(HIGH)
Figure 16. Start Condition Hold Time vs Supply Voltage
Figure 19. Input Data Hold Time vs Supply Voltage
(LOW)
Typical Performance Curves - continued
0
0.2
0.4
0.6
0.8
1
0 1 2 3 4 5 6
Start Condition Hold Time: t HD:STA(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
-0.2
0
0.2
0.4
0.6
0.8
1
0123456
Start Condition Setup Time: t SU:STA (µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
-200
-150
-100
-50
0
50
0123456
Input Data Hold Time: t HD:DAT (ns)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
-200
-150
-100
-50
0
50
0 1 2 3 4 5 6
Input Data Hold Time: t HD:DAT(ns)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
Datasheet
9/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Figure 23. ‘H’ Output Data Delay Time vs Supply Voltage
Figure 21. Input Data Setup Time vs Supply Voltage
(LOW)
Figure 22. ‘LOutput Data Delay Time vs Supply Voltage
Figure 20. Input Data Setup Time vs Supply Voltage
(HIGH)
Typical Performance Curves - continued
-200
-100
0
100
200
300
0123456
Input Data Setup Time: t SU:DAT(ns)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
-200
-100
0
100
200
300
0 1 2 3 4 5 6
Input Data Setup Time: t SU:DAT(ns)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.5
1
1.5
2
0 1 2 3 4 5 6
L Output Data Delay Time: t PD(µs)
Supply Voltage: Vcc(V)
SPEC
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.5
1
1.5
2
0123456
H Output Data Delay Time: t PD (µs)
Supply Voltage: Vcc(V)
SPEC
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
Datasheet
10/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Figure 24. Stop Condition Setup Time vs Supply Voltage
Figure 27. Noise Spike Width vs Supply Voltage
(SCL H)
Figure 25. Bus Free Time vs Supply Voltage
Figure 26. Write Cycle Time vs Supply Voltage
Typical Performance Curves - continued
-0.5
0
0.5
1
1.5
2
0 1 2 3 4 5 6
Stop Condition Setup Time: t SU:STO(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
1
2
3
4
5
6
0 1 2 3 4 5 6
Write Cycle Time: t WR(ms)
Supply Voltage: Vcc(V)
Ta=-40
Ta= 25
Ta= 85
SPEC
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 2 3 4 5 6
Noise Spike Width(SCL H):tI(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.5
1
1.5
2
0123456
Bus Free Time : t BUF(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
Datasheet
11/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Figure 29. Noise Spike Width vs Supply Voltage
(SDA H)
Figure 30. Noise Spike Width vs Supply Voltage
(SDA L)
Figure 31. WP Hold Time vs Supply Voltage
Figure 28. Noise Spike Width vs Supply Voltage
(SCL L)
Typical Performance Curves - continued
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 2 3 4 5 6
Noise Spike Width(SCL L): tI(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.1
0.2
0.3
0.4
0.5
0.6
0123456
Noise Spike Width(SDA L): tI(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.2
0.4
0.6
0.8
1
1.2
0 1 2 3 4 5 6
WP Hold Time : t HD:WP(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 2 3 4 5 6
Noise Spike Width(SDA H): tI(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
Datasheet
12/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Figure 32. WP Setup Time vs Supply Voltage
Figure 33. WP High Period vs Supply Voltage
Typical Performance Curves - continued
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0123456
WP Setup Time: t SU:WP(µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
0
0.2
0.4
0.6
0.8
1
1.2
0 1 2 3 4 5 6
WP High Period: t HIGH:WP ( µs)
Supply Voltage: Vcc(V)
SPEC
Ta=-40℃
Ta= 25℃
Ta= 85℃
Datasheet
13/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
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..
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 (
W/R
--- READ /
WRITE
) of slave address is used for designating write or read operation,
and is as shown below.
Setting
W/R
to 0 ------- write (setting 0 to word address setting of random read)
Setting
W/R
to 1 ------- read
Slave Address
Maximum Number of
Connected Buses
1 0 1 0 A2 A1 A0 R/W
――
8
8 9 8 9 8 9
S P
condition condition
ACK
STOP
ACK
DATA
DATA
ADDRESS
START
R/W
ACK
1-7
SDA
SCL
1-7
1-7
Figure 34. Data Transfer Timing
Datasheet
14/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
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.
(2) During internal write execution, all input commands are ignored, therefore ACK is not returned.
(3) Data is written to the address designated by word address (n-th address)
(4) By issuing stop bit after 8bit data input, internal write to memory cell starts.
(5) When internal write is started, command is not accepted for tWR (5ms at maximum).
(6) 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 x 64byte=320ms (Max).
2. Internal Address Increment
Page write mode (in the case of BR24T256-W)
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.
A1
A2
WA
14
1
1
0
0
W
R
I
T
E
S
T
A
R
T
R
/
W
S
T
O
P
1st WORD
ADDRESS
DATA
SLAVE
ADDRESS
A0
D0
A
C
K
SDA
LINE
A
C
K
A
C
K
WA
13
WA
12
WA
11
WA
0
A
C
K
2nd WORD
ADDRESS
D7
*
Figure 35. Byte Write Cycle
Figure 36. Page Write Cycle
D0
D7
A
C
K
2nd WORD
ADDRESS(n)
WA
0
WA
13
WA
12
WA
11
* Don't Care bit
*
WA7 WA6 WA5 WA4 WA3 WA2 WA1 WA0
00000000
00000001
00000010
0 0111110
0 0111111
0 0000000
Increment
3Eh
Significant bit is fixed.
No digit up
* Don't Care bit
W
R
I
T
E
S
T
A
R
T
R
/
W
A
C
K
S
T
O
P
1st WORD
ADDRESS(n)
SDA
LINE
A
C
K
A
C
K
DATA(n+63)
A
C
K
SLAVE
ADDRESS
1
0
0
1
A0
A1
A2
WA
14
D0
DATA(n)
For example, when it is started from address 1Eh,
For example, when it is started from address 3Eh,
then, increment is made as below,
3Eh3Fh00h01h···. Please take note.
*3Eh···3E in hexadecimal, therefore, 00111110 is a
binary number.
Datasheet
15/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
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.
(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 -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 ‘Lto ‘H’ while SCL signal is 'H'.
Figure 37. Random Read Cycle
Figure 38. Current Read Cycle
Figure 39. Sequential Read Cycle (in the case of current read cycle)
* Dont Care bit
A2
A0
A1
A1
A2
W
R
I
T
E
S
T
A
R
T
R
/
W
A
C
K
S
T
O
P
1st WORD
ADDRESS(n)
SDA
LINE
A
C
K
A
C
K
DATA(n)
A
C
K
SLAVE
ADDRESS
1
0
0
0
1
0
A0
D7
D0
2nd WORD
ADDRESS(n)
A
C
K
S
T
A
R
T
SLAVE
ADDRESS
1
0
0
0
1
0
R
/
W
R
E
A
D
WA
0
*
WA
14
WA
13
WA
12
WA
11
S
T
A
R
T
S
T
O
P
SDA
LINE
A
C
K
DATA(n)
A
C
K
SLAVE
ADDRESS
1
0
0
0
1
A0
A1
A2
D0
D7
R
/
W
R
E
A
D
R
E
A
D
S
T
A
R
T
R
/
W
A
C
K
S
T
O
P
DATA(n)
SDA
LINE
A
C
K
A
C
K
DATA(n+x)
A
C
K
SLAVE
ADDRESS
1
0
0
0
1
0
A0
A1
A2
D0
D7
D0
D7
Datasheet
16/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
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.
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,
W/R
= 0, then to carry out current read cycle after write, slave address with
W/R
= 1 is sent. If ACK
signal sends back 'L', and then execute word address input and data output and so forth..
1
2
13
14
SCL
Dummy clock×14
Start×2
SCL
Figure 40-(a). The Case of Dummy Clock×14 + START+START+ Command Input
*Start command from START input.
2
1
8
9
Dummy clock×9
Start
Figure 40-(b). The Case of START + Dummy Clock×9 + START + Command Input
Start
Normal command
Normal command
Normal command
Normal command
Start×9
SDA
SDA
SCL
SD
A
1
2
3
8
9
7
Figure 40-(c). START×9 + Command Input
Normal command
Normal command
SDA
Slave
address
Word
address
···
···
S
T
A
R
T
First write command
A
C
K
H
A
C
K
L
Slave
address
Slave
address
Slave
address
Data
Write command
During internal write,
ACK = HIGH is returned.
After completion of internal write,
ACK=LOW is returned, so input next
word address and data in succession.
tWR
tWR
Second write command
S
T
A
R
T
S
T
A
R
T
S
T
A
R
T
S
T
A
R
T
S
T
O
P
S
T
O
P
A
C
K
H
A
C
K
H
A
C
K
L
A
C
K
L
Figure 41. Case of Continuous Write by Acknowledge Polling
Datasheet
17/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
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.
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.
·Rise of D0 taken clock
SCL
D0
ACK
Enlarged view
SCL
SDA
ACK
D0
·Rise of SDA
SDA
WP
WP cancel invalid area
WP cancel valid area
Data is not written.
Figure 42. WP Valid Timing
Slave
address
D7
D6
D5
D4
D3
D2
D1
D0
Data
tWR
SDA
D1
S
T
A
R
T
A
C
K
L
A
C
K
L
A
C
K
L
A
C
K
L
S
T
O
P
Word
address
Figure 43. Case of Cancel by Start, Stop Condition during Slave Address Input
SCL
SDA
1
1
0
0
Start condition
Stop condition
Enlarged view
WP cancel invalid area
Datasheet
18/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
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
Ex.) Vcc =3V IL=10µA VIH=0.7 Vcc
From (2)
30 [kΩ]
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.
(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)
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 to several ten is
recommended in consideration of drive performance of output port of microcontroller.
Figure 44. I/O circuit diagram
Microcontroller
R
PU
A
SDA terminal
I
L
I
L
Bus line
capacity
CBUS
BR24TXX
RPU
0.8Vcc - VIH
IL
RPU
0.8 × 3 - 0.7 × 3
10 × 10-6
RPU
Vcc - VOL
RPU
IOL
Vcc - VOL
IOL
RPU
3 - 0.4
3 × 10-3
Datasheet
19/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
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.
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.
Ex)VCC=3V VIL=0.3VCC VOL=0.4V RPU=20kΩ
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.
EX) VCC=3V I=10mA
(Vcc - VOL) × RS
RPU+RS
R
PU
Microcontroller
RS
EEPROM
Figure 45. I/O Circuit Diagram
Figure 46. Input / Output Collision Timing
ACK
'L' output of EEPROM
'H' output of microcontroller
Over current flows to SDA line by 'H'
output of microcontroller and 'L'
output of EEPROM.
SCL
SDA
Microcontroller
EEPROM
'L'output
R
S
R
PU
'H' output
Over current I
Figure 48. I/O Circuit Diagram
Figure 47. I/O Circuit Diagram
RPU
Micro controller
RS
EEPROM
IOL
A
Bus line
capacity
CBUS
VOL
VCC
VIL
+VOL+0.1Vcc VIL
RS
× RPU
VIL - VOL - 0.1Vcc
1.1Vcc - VIL
1.67 [kΩ]
RS
0.3 × 3 - 0.4 - 0.1 × 3
1.1 × 3 - 0.3 × 3
× 20 × 103
RS
3
10 × 10-3
300 [Ω]
Vcc
RS
I
RS
Vcc
I
Datasheet
20/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
I/O Equivalence Circuit
1. Input (A0, A1, A2, SCL, WP)
2. Input / Output (SDA)
Figure 49. Input Pin Circuit Diagram
Figure 50. Input / Output Pin Circuit Diagram
Datasheet
21/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
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.
tOFF
tR
Vbot
0
VCC
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'.
(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.
Recommended conditions of tR, tOFF,Vbot
tR
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
Figure 52. When SCL= 'H' and SDA= 'L'
Figure 53. When SCL='L' and SDA='L'
tLOW
tSU:DAT
tDH
After Vcc becomes stable
SCL
V
CC
SDA
tSU:DAT
After Vcc becomes stable
Datasheet
22/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
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.
Datasheet
23/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Part Numbering
B
R
2
4
T
2
5
6
x
x
x
-
W
x
x
x
BUS Type
24I2C
Operating Temperature/
Power Source Voltage
-40 to +85/
1.6V to 5.5V
Capacity
256=256K
Package
Blank
:DIP-T8 (1), DIP8K
F
:SOP8
FJ
:SOP-J8
FV
: SSOP-B8
FVT
: TSSOP-B8
Double Cell
Blank
Z
:DIP-T8 (1), SOP8, SOP-J8, SSOP-B8, TSSOP-B8
:DIP8K
Packaging and Forming Specification
E2
: Embossed tape and reel
(SOP8,SOP-J8, SSOP-B8,TSSOP-B8)
None
: Tube
(DIP-T8 (1), DIP8K)
(1) Not Recommended for New Designs. Recommend BR24T256-WZ.
Datasheet
24/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Physical Dimension and Packing Information
Package Name
DIP-T8
<Container Information>
Datasheet
25/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Physical Dimension and Packing Information - continued
Package Name
DIP8K
Datasheet
26/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Physical Dimension and Packing Information - continued
Package Name
SOP8
(UNIT: mm)
PKG: SOP8
Drawing No.: EX112-5001-1
(Max 5.35 (include.BURR))
Datasheet
27/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Physical Dimension and Packing Information - continued
Package Name
SOP-J8
Datasheet
28/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Physical Dimension and Packing Information - continued
Package Name
SSOP-B8
Datasheet
29/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Physical Dimension and Packing Information - continued
Package Name
TSSOP-B8
Datasheet
30/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Marking Diagrams (TOP VIEW)
DIP-T8 (TOP VIEW)
BR24T256
Part Number Marking
LOT Number
SOP8 (TOP VIEW)
Part Number Marking
LOT Number
1PIN MARK
SOP-J8 (TOP VIEW)
Part Number Marking
LOT Number
1PIN MARK
TSSOP-B8 (TOP VIEW)
Part Number Marking
LOT Number
1PIN MARK
4 T 2 5 6
4 T 2 5 6
4 T 2 5 6
SSOP-B8 (TOP VIEW)
Part Number Marking
LOT Number
1PIN MARK
T 2 5 6
4
DIP8K (TOP VIEW)
BR24T256
Part Number Marking
LOT Number
Datasheet
31/31
BR24T256-W
TSZ02201-0R2R0G100140-1-2
17.Dec.2018 Rev.004
©2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 15 001
www.rohm.com
Revision History
Date
Revision
Changes
18.May.2012
001
New Release
25.Feb.2013
002
Update some English words, sentences’ descriptions, grammar and formatting.
Add tF2 in Serial Input / Output Timing
31.May.2013
003
P1 Change format of package line-up table.
P.2 Add VESD in Absolute Maximum Ratings
P.4 Add directions in Pin Descriptions
17.Dec.2018
004
Add DIP8K
Change DIP-T8 to Not Recommended for New Designs
Change Physical Dimension Tape and Reel Information
Change the fonts and format
Notice-PGA-E Rev.004
© 2015 ROHM Co., Ltd. All rights reserved.
Notice
Precaution on using ROHM Products
1. Our Products are designed and manufactured for application in ordinary electronic equipment (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
intend to use our Products in devices requiring extremely high reliability (such as medical equipment (Note 1), transport
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 ROHMs Products for Specific
Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASS
CLASS
CLASSb
CLASS
CLASS
CLASS
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 (Exclude cases where no-clean type fluxes is used.
However, recommend sufficiently about the residue.) ; 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 depending on ambient temperature. When used in sealed area, confirm that it is the use in
the range that does not exceed the maximum junction 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 on a surface-mount products, the flow soldering method must
be used on a through hole mount products. If the flow soldering method is preferred on a surface-mount products,
please consult with the ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice-PGA-E Rev.004
© 2015 ROHM Co., Ltd. All rights reserved.
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
A two-dimensional barcode printed on ROHM Products label is for ROHMs 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 concerned goods might be fallen under listed items of export control prescribed by Foreign exchange and Foreign
trade act, please consult with ROHM 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.
2. ROHM shall not have any obligations where the claims, actions or demands arising from the combination of the
Products with other articles such as components, circuits, systems or external equipment (including software).
3. 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 Products or the information contained in this document. Provided, however, that ROHM
will not assert its intellectual property rights or other rights against you or your customers to the extent necessary to
manufacture or sell products containing the Products, subject to the terms and conditions herein.
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.
DatasheetDatasheet
Notice – WE Rev.001
© 2015 ROHM Co., Ltd. All rights reserved.
General Precaution
1. Before you use our Products, you are requested to carefully read this document and fully understand its contents.
ROHM shall not be in any way responsible or liable for failure, malfunction or accident arising from the use of any
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this document is current as of the issuing date and subject to change without any prior
notice. Before purchasing or using ROHMs Products, please confirm the latest information with a ROHM sales
representative.
3. The information contained in this document is provided on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate and/or error-free. ROHM shall not be in any way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccuracy or errors of or
concerning such information.
Datasheet
Part Number br24t256f-w
Package SOP8
Unit Quantity 2500
Minimum Package Quantity 2500
Packing Type Taping
Constitution Materials List inquiry
RoHS Yes
br24t256f-w - Web Page
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