TECHNICAL NOTE
Double-cell Memory for Plug & Play
DDR/DDR2
(For memory module) SPD Memory
BR34E02-W
●Description
BR34E02FVT-W is 256×8 bit Electrically Erasable PROM (Based on Serial Presence Detect)
●Features
・256×8 bit architecture serial EEPROM
・Wide operating voltage range: 1.7V-3.6V
・Two-wire serial interface
・High reliability connection using Au pads and Au wires
・Self-Timed Erase and Write Cycle
・Page Write Function (16byte)
・Write Protect Mode
Settable Reversible Write Protect Function: 00h-7Fh
Write Protect 1 (Onetime Rom) : 00h-7Fh
Write Protect 2 (Hardwire WP PIN) : 00h-FFh
・Low Power consumption
Write (at 1.7V ) : 0.4mA (typ.)
Read (at 1.7V ) : 0.1mA(typ.)
Standby ( at 1.7V ) : 0.1μA(typ.)
・DATA security
Write protect feature (WP pin)
Inhibit to WRITE at low VCC
・Compact package: TSSOP-B8, VSON008X2030
・High reliability fine pattern CMOS technology
・Rewriting possible up to 1,000,000 times
・Data retention: 40 years
・Noise reduction Filtered inputs in SCL / SDA
・Initial data FFh at all addresses
●BR34E02-W Series
Capacity Bit format Type Power Source Voltage TSSOP-B8 VSON008X2030
2Kbit 256X8 BR34E02-W 1.7V～3.6V ● ●
Ver.A Aug.2007
2/19
●Absolute Maximum Ratings (Ta=25℃)
Parameter Symbol Rating Unit
Supply Voltage VCC -0.3～+6.5 V
330(BR34E02FVT-W) *1
Power Dissipation Pd 300(BR34E02NUX-W) *2 mW
Storage Temperature Tstg -65～+125 ℃
Operating Temperature Topr -40～+85 ℃
Terminal Voltage (A0) - -0.3～10.0 V
Terminal Voltage (etcetera) - -0.3～VCC+0.3 V
* Reduce by 3.3mW(*1), 3.0 mW(*2)/°C over 25°C
●Recommended operating conditions
Parameter Symbol Rating Unit
Supply Voltage VCC 1.7～3.6 V
Input Voltage ＶIN 0～VCC V
●Memory cell characteristics（Ta=25℃, VCC=1.7V～3.6V）
Specification
Parameter Min. Typ. Max. Unit
Write / Erase Cycle *1 1,000,000 － － Cycles
Data Retention *1 40 － － Years
*1:Not 100% TESTED
●Electrical characteristics - DC（Unless otherwise specified Ta=-40℃～+85℃, VCC=1.7V～3.6V）
Specification
Parameter Symbol
Min. Typ. Max. Unit Test Condition
"H" Input Voltage VIH1 0.7 VCC - Vcc+0.3 V
"L" Input Voltage VIL1 - - 0.3 VCC V
"L" Output Voltage 1 VOL1 -0.3 - 0.4 V
IOL=2.1mA，2.5V≦VCC≦3.6V（SDA）
"L" Output Voltage 2 VOL2 - - 0.2 V
IOL=0.7mA，1.7V≦VCC＜2.5V（SDA）
Input Leakage Current 1 ILI1 -1 - 1 μAVIN=0V～VCC（A0,A1,A2,SCL）
Input Leakage Current 2 ILI2 -1 - 15 μAVIN=0V～VCC（WP）
Input Leakage Current 3 ILI3 -1 - 20 μAVIN=VHV(A0)
Output Leakage Current ILO -1 - 1 μAVOUT=0V～VCC
ICC1 - - 1.0 mA
VCC=1.7V,fSCL=100ｋHz，tWR=5ms
Byte Write
Page Write
Write Protect
ICC2 - - 3.0 mA
VCC =3.6V,fSCL=100ｋHz, tWR=5ms
Byte Write
Page Write
Write Protect
Operating Current
ICC3 - - 0.5 mA
VCC =3.6V,fSCL=100ｋHz
Random Read
Current Read
Sequential Read
Standby Current ISB - - 2.0 μAVCC =3.6V,SDA,SCL= VCC
A0,A1,A2=GND,WP=GND
A0 HV Voltage VHV 7 - 10 V
VHV-Vcc≧4.8V
○Note: This IC is not designed to be radiation-resistant.
3/19
SDA
(IN)
SCL
SDA
(OUT)
tHD:STA tHD:DATtSU:DAT
tBUF t
PD tDH
tLOW
tHIGH tR t
F
SDA
SCL
tSU:STA tSU:STO tHD:STA
START BIT STOP BI
T
SDA
SCL
D0 ACK
STOP
CONDITION
START
CONDITION
tWR
WRITE DATA(n)
Fig.1-(a) Synchronous Data Timing
Fig.1-(b) Start/Stop Bit Timing
Fig.1-(c) Write Cycle Timing
○ SDA data is latched into the chip at the rising edge
○ of SCL clock.
○ Output data toggles at the falling edge of SCL clock.
Fig.1-(d) WP Timing Of The Write Operation
SCL
WP
SCL
WP
Fig.1-(e) WP Timing Of The Write Cancel Operation
○For WRITE operation, WP must be "Low" from the rising edge of
the clock (which takes in D0 of first byte) until the end of tWR.
(See Fig.1-(d) ) During this period, WRITE operation can be
canceled by setting WP "High".（See Fig.1-(e)）
○When WP is set to "High" during tWR, WRITE operation is
immediately ceased, making the data unreliable. It must then
be re-written.
●Electrical characteristics - AC（Unless otherwise specified Ta=-40℃～+85℃, VCC =1.7V～3.6V）
FAST-MODE
2.5V≦VCC≦5.5V
STANDARD-MODE
1.7V≦VCC≦5.5V
Parameter Symbol
Min. Typ. Max. Min. Typ. Max.
Unit
Clock Frequency fSCL － － 400 － － 100 kHz
Data Clock High Period tHIGH 0.6 － － 4.0 － － μs
Data Clock Low Period tLOW 1.2 － － 4.7 － － μs
SDA and SCL Rise Time *1 tR － － 0.3 － － 1.0 μs
SDA and SCL Fall Time *1 tF － － 0.3 － － 0.3 μs
Start Condition Hold Time tHD:STA 0.6 － － 4.0 － － μs
Start Condition Setup Time tSU:STA 0.6 － － 4.7 － － μs
Input Data Hold Time tHD:DAT 0 － － 0 － － ns
Input Data Setup Time tSU:DAT 100 － － 250 － － ns
Output Data Delay Time tPD 0.1 － 0.9 0.1 － 3.5 μs
Output Data Hold Time tDH 0.1 － － 0.1 － － μs
Stop Condition Setup Time tSU:STO 0.6 － － 4.0 － － μs
Bus Free Time tBUF 1.2 － － 4.7 － － μs
Write Cycle Time tWR － － 5 － － 5 ms
Noise Spike Width (SDA
and SCL) tI － － 0.1 － － 0.1 μs
WP Hold Time tHD：WP 0 － － 0 － － ns
WP Setup Time tSU：WP 0.1 － － 0.1 － － μs
WP High Period tHIGH：WP 1.0 － － 1.0 － － μs
*1：Not 100％ TESTED
■Fast / Standard Modes
Fast mode and Standard mode differ only in operation frequency. Operations performed at 100kHz are considered in
"Standard-mode", while those conducted at 400kHz are in "Fast-mode".
Please note that these clock frequencies are maximum values. At lower power supply voltage it is difficult to operate at high
speeds.
The EEPROM can operate at 400kHz, between 2.5V and 3.6V, and at 100kHz from 1.7V-2.5V.
●Synchronous Data Timing
t
WR
ｔ
HIGH
:
WP
SDA
DATA(n)
ｔＨＤ：WP
STOP BIT
D1 D0
ACK ACK
DATA(1)
DATA(n)
tSU：WP
tWR
SDA D0 ACK ACK D1
DATA(1)
4/19
*1 Open drain output requires a pull-up resistor.
*2 WP Pin has a Pull-Down resistor. Please leave unconnected or
connect to GND when not in use.
Fig.7 "L" Output Voltage VOL2-IOL2
(VCC=1.7V)
8
7
6
5 4
3
2
1
SDA
SCL
WP
VCC
GND
A2
A1
A0
ADDRESS
DECODER
SLAVE , WORD
ADDRESS REGISTER
DATA
REGISTER
CONTOROL LOGIC
HIGH VOLTAGE GEN. VCC LEVEL DETECT
8bit
8bit
8bit
ACK
START STOP
PROTECT_MEMORY_ARRY
2Kbit_MEMORY_ARRY
●Block diagram
●Pinout diagram and description
Pin Name Input/Output Functions
VCC － Power Supply
GND － Ground 0V
A0,A1,A2 IN Slave Address Set.
SCL IN Serial Clock Input
SDA IN / OUT Slave and Word Address, *1
Serial Data Input, Serial Data Output
WP IN Write Protect Input *2
●Electrical characteristics curves
The following characteristic data are typ. value.
Fig.6 "L" Output Voltage VOL1-IOL1
(VCC=2.5V)
Fig.8 Input Leakage Current ILI1
(A0,A1,A2,SCL,SDA)
Fig.9 Input Leakage Current ILI2
(WP)
8
7
6
5
1
2
3
4
V
CC
WP
SCL
SDA
A
0
A
1
A
2
GND
Fig.3 Pin Configuration
BR34E02FVT-W
BR34E02NUX-W
Fig.5 "L" Input Voltage VIL
(A0,A1,A2,SCL,SDA,WP)
Fig.4 "H" Input Voltage VIH
(A0,A1,A2,SCL,SDA,WP)
Fig.2 Block Diagram
0
0.2
0.4
0.6
0.8
1
01234
IOL1[mA]
VOL1[V]
Ta=85℃
SPEC
Ta=25℃
Ta=-40℃
0
1
2
3
4
5
6
01234
VCC[V]
VIH1,2[V]
SPEC
Ta=85℃
Ta=-40℃
Ta=25℃
0
1
2
3
4
5
6
01234
VCC[V]
VIL1,2[V]
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC
0
0.2
0.4
0.6
0.8
1
01234
IOL2[mA]
VOL2[V]
Ta=85℃
SPEC Ta=25℃
Ta=-40℃
0
0.2
0.4
0.6
0.8
1
1.2
01234
VCC[V]
ILI1[ μA]
Ta=85℃
Ta=25℃
Ta=-40℃
SPEC
0
4
8
12
16
01234
VCC[V]
ILI2[µA]
Ta=85℃
Ta=25℃
Ta=-40℃
SPEC
5/19
Fig.10 Write Operating Current ICC1,2
(fSCL=100kHz,400kHz)
Fig.15 Data Clock Low Period tLow
Fig.11 Read Operating Current ICC3
(fSCL=400kHz)
Fig.13 Clock Frequency fSCL
Fig.17 Start Condition Setup Time
tSU:STA
Fig.12 Standby Current ISB
Fig.14 Data Clock High Period tHigh
Fig.19 Data Hold Time
tHD:DAT(LOW)
Fig.21 Input Data Setup Time
tSU:DAT(LOW)
Fig.16 Start Condition Hold Time
tHD:STA
0
0.1
0.2
0.3
0.4
0.5
0.6
01234
VCC[V]
ICC3[mA]
Ta=-40℃
SPEC
Ta=85℃
Ta=25℃
ｆＳＣＬ=100kHz
DATA=AAh
0
0.5
1
1.5
2
2.5
3
3.5
01234
VCC[V]
ICC1,2[mA]
SPEC1
SPEC2
ｆSCL=400kHz(VCC≧2.5V)
fSCL=100kHz(1.7V≦Vcc＜２．５V)
DATA=AA
Ta=25℃
Ta=85℃
Ta=-40℃
0
0.5
1
1.5
2
2.5
01234
VCC[V]
ISB[µA]
Ta=-40℃
SPEC
Ta=85℃
Ta=25℃
0
1
2
3
4
5
01234
VCC[V]
tHIGH[µs]
Ta=-40℃
SPEC2
Ta=85℃
Ta=25℃
SPEC1
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
1
10
100
1000
10000
01234
VCC[V]
fSCL[kHz]
Ta=-40℃
SPEC1
Ta=85℃
Ta=25℃
SPEC2
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
1
2
3
4
5
01234
VCC[V]
tLOW[µs]
SPEC2
Ta=-40℃
Ta=85℃
Ta=25℃
SPEC1
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
Fig.18 Data Hold Time
tHD:DAT(High)
-200
-150
-100
-50
0
50
01234
VCC[V]
tHD:DAT(HIGH)[µs]
SPEC1,2
Ta=-40℃
Ta=85℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
1
2
3
4
5
01234
VCC[V]
tHD:STA[µs]
Ta=-40℃
SPEC2
Ta=85℃
Ta=25℃
SPEC1
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
1
2
3
4
5
01234
VCC[V]
tSU:STA[µs]
Ta=-40℃
SPEC2
Ta=85℃
Ta=25℃
SPEC1
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
-200
-100
0
100
200
300
01234
VCC[V]
tSU:DAT(HIGH)[ns]
SPEC1 Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
-200
-100
0
100
200
300
01234
VCC[V]
tSU:DAT(LOW)[ns]
SPEC2
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
-200
-150
-100
-50
0
50
01234
VCC[V]
tHD:DAT(LOW)[µs]
SPEC1,2
Ta=-40℃
Ta=85℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
Fig.20 Input Data Setup Time
tSU:DAT(HIGH)
6/19
Fig.24 Stop Condition Setup Time
tSU:STO
Fig.25 Bus Free Time
tBUF Fig.26 Write Cycle Time
tWR
Fig.31 WP Setup Time
tSU:WP
Fig.32 WP High Period
tHigh:WP
Fig.30 Noise Spike Width
tI(SDA L)
Fig.23 Output Data Hold Time
tDH
Fig.22 Output Data Delay Time
tPD
Fig.29 Noise Spike Width
tI(SDA H)
Fig.27 Noise Spike Width
tI(SCL H)
Fig.28 Noise Spike Width
tI(SCL L)
0
1
2
3
4
01234
VCC[V]
tDH[μs]
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1
SPEC2
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
1
2
3
4
01234
VCC[V]
tPD[μs]
SPEC2
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1
SPEC1
SPEC2
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
1
2
3
4
5
01234
VCC[V]
tSU:STO[µs]
SPEC2
Ta=85℃
Ta=-40
℃
Ta=25℃
SPEC1
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
1
2
3
4
5
01234
VCC[V]
tBUF[µs]
SPEC2
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
1
2
3
4
5
6
01234
VCC[V]
tWR[ms]
SPEC1,2
Ta=85℃
Ta=-40℃Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE 0
0.1
0.2
0.3
0.4
0.5
0.6
01234
VCC[V]
tI(SCL H)[μs]
SPEC1,2
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
0.1
0.2
0.3
0.4
0.5
0.6
01234
VCC[V]
tI(SCL L)[μs]
SPEC1,2
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
0.1
0.2
0.3
0.4
0.5
0.6
01234
VCC[V]
tI(SDA H)[μs]
SPEC1,2
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
0.1
0.2
0.3
0.4
0.5
0.6
01234
VCC[V]
tI(SDA L)[μs]
SPEC1,2
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
-0.6
-0.4
-0.2
0
0.2
01234
VCC[V]
tSU:WP[μs]
SPEC1,2
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
0
0.2
0.4
0.6
0.8
1
1.2
01234
VCC[V]
tHIGH:WP[μs]
SPEC1,2
Ta=85℃
Ta=-40℃
Ta=25℃
SPEC1:FAST-MODE
SPEC2:STANDARD-MODE
7/19
●Data transfer on the I2C BUS
○Data transfer on the I2C BUS
The BUS is considered to be busy after the START condition and free a certain time after the STOP condition.
Every SDA byte must be 8-bits long and requires an ACKNOWLEDGE signal after each byte. The devices have Master
and Slave configurations. The Master device initiates and ends data transfer on the BUS and generates the clock
signals in order to permit transfer.
The EEPROM in a slave configuration is controlled by a unique address. Devices transmitting data are referred to as
the Transmitter. The devices receiving the data are called Receiver.
○START Condition (Recognition of the START bit)
・All commands are proceeded by the start condition, which is a High to Low transition of SDA when SCL is High.
・The device continuously monitors the SDA and SCL lines for the start condition and will not respond to any command
until this condition has been met. (See Fig.1-(b) START/STOP Bit Timing)
○STOP Condition (Recognition of STOP bit)
・All communications must be terminated by a stop condition, which is a Low to High transition of SDA when SCL is
High. (See Fig.1-(b) START/STOP Bit Timing)
○Write Protect By Soft Ware
・Set Write Protect command and permanent set Write Protect command set data of 00h～7Fh in 256 words write
protection block. Clear Write Protect command can cancel write protection block which is set by set write Protect
command. Cancel of write protection block which is set by permanent set Write Protect command at once is
impossibility. When these commands are carried out, WP pin must be OPEN or GND.
○Acknowledge
・ Acknowledge is a software used to indicate successful data transfers. The Transmitter device will release the BUS
after transmitting eight bits. When inputting the slave address during write or read operation, the Transmitter is the μ
-COM. When outputting the data during read operation, the Transmitter is the EEPROM.
・During the ninth clock cycle the Receiver will pull the SDA line Low to verify that the eight bits of data have been
received. (When inputting the slave address during write or read operation, EEPROM is the receiver. When
outputting the data during read operation the receiver is the μ-COM.)
・The device will respond with an Acknowledge after recognition of a START condition and its slave address (8bit).
・In WRITE mode, the device will respond with an Acknowledge after the receipt of each subsequent 8-bit word (word
address and write data).
・In READ mode, the device will transmit eight bits of data, release the SDA line, and monitor the line for an
Acknowledge.
・If an Acknowledge is detected and no STOP condition is generated by the Master, the device will continue to transmit
the data. If an Acknowledge is not detected, the device will terminate further data transmissions and await a STOP
condition before returning to standby mode.
○Device Addressing
・Following a START condition, the Master outputs the Slave address to be accessed. The most significant four bits
of the slave address are the “device type indentifier.” For this EEPROM it is “1010.” (For WP register access this code
is "0110".)
・The next three bits identify the specified device on the BUS (device address). The device address is defined by the
state of the A0,A1 and A2 input pins. This IC works only when the device address input from the SDA pin corresponds
to the status of the A0,A1 and A2 input pins. Using this address scheme allows up to eight devices to be connected to
the BUS.
8/19
・The last bit of the stream (R/W…READ/WRITE) determines the operation to be performed.
R/W=0 ････ WRITE (including word address input of Random Read)
R/W=1 ････ READ
Slave Address Set Pin Device Type Device Address Read Write Mode Access Area
A2 A1 A0 1010 A2 A1 A0 R/W 2kbit Access to Memory
A2 A1 A0 A2 A1 A0 R/W Access to Permanent Set Write
Protect Memory
GND GND VHV 0 0 1 R/W Access to Set Write Protect Memroy
GND Vcc VHV
0110
0 1 1 R/W Access to Clear Write Protect MEmory
○WRITE PROTECT PIN(WP)
When WP pin set to Vcc (H level), write protect is set for 256 words (all address). When WP pin set to GND (L level),
it is enable to write 256 words (all address).
If permanent protection is done by Write Protect command, lower half area (00～7Fh address) is inhibited writing
regardless of WP pin state.
WP pin has a Pull-Down resistor. Please be left unconnected or connect to GND when WP feature is not in use.
○Confirm Write Protect Resistor by ACK
According to state of Write Protect Resistor, ACK is as follows.
State of Write
Protect Registor WP Input Input Command ACK Address ACK Data ACK Write
Cycle(tWR)
PSWP, SWP, CWP No ACK - No ACK No ACK No
In case,
protect by PSWP - Page or Byte Write
(00～7Fh) ACK WA7～WA0 ACK D7～D0 No ACK No
SWP No ACK - No ACK - No ACK No
CWP ACK - ACK -
ACK Yes
PSWP ACK - ACK -
ACK Yes
0
Page or Byte Write
(00～7Fh) ACK WA7～WA0 ACK D7～D0 No ACK No
SWP No ACK - No ACK - No ACK No
CSP ACK - ACK - No ACK No
PSWP ACK - ACK - No ACK No
In case,
protect by SWP
1
Page or Byte Write ACK WA7～WA0 ACK D7～D0 No ACK No
PSWP, SWP, CWP ACK - ACK - ACK Yes
0 Page or Byte Write ACK WA7～WA0 ACK D7～D0 ACK Yes
PSWP, SWP, CWP ACK - ACK - No ACK No
In case,
Not protect 1 Page or Byte Write ACK WA7～WA0 ACK D7～D0 No ACK No
- is Don’t Care
State of Write Protect Registor Command ACK Address ACK Data ACK
In case, protect by PSWP PSWP, SWP, CWP No ACK - No ACK - No ACK
SWP No ACK - No ACK - No ACK
CWP ACK - No ACK -
No ACK
In case, protect by SWP
PSWP ACK - No ACK -
No ACK
In case, Not protect PSWP, SWP, CWP ACK - No ACK -
No ACK
9/19
W
R
I
T
E
S
T
A
R
T
R
/
W
A
C
K
S
T
O
P
WORD
ADDRESS(n) DATA(n)
SDA
LINE
A
C
K
A
C
K
DATA(n+15)
A
C
K
SLAVE
ADDRESS
100
1A0A1A2 WA
7D0D7 D0
WA
0
●Command
○Write Cycle
During WRITE CYCLE operation data is written in the EEPROM. The Byte Write Cycle is used to write only one byte. In
the case of writing continuous data consisting of more than one byte, Page Write is used. The maximum bytes that can
be written at one time is 16 bytes.
・With this command the data is programmed into the indicated word address.
・When the Master generates a STOP condition, the device begins the internal write cycle to the nonvolatile memory
array.
・Once programming is started no commands are accepted for tWR (5ms max.).
・This device is capable of sixteen-byte Page Write operations.
・If the Master transmits more than sixteen words prior to generating the STOP condition, the address counter will “roll
over” and the previously transmitted data will be overwritten.
・When two or more byte of data are input, the four low order address bits are internally incremented by one after the
receipt of each word, while the four higher order bits of the address (WA7～WA4) remain constant.
A1A2 WA
7D7
1100
W
R
I
T
E
S
T
A
R
T
R
/
W
S
T
O
P
WORD
ADDRESS DAT
A
SLAVE
ADDRESS
A0 WA
0D0
A
C
K
SDA
LINE
A
C
K
A
C
K
Fig.33 Byte Write Cycle Timing
Fig.34 Page Write Cycle Timing
10/19
●Command
○Read Cycle
During Read Cycle operation data is read from the EEPROM. The Read Cycle is composed of Random Read Cycle and
Current Read Cycle. The Random Read Cycle reads the data in the indicated address.
The Current Read Cycle reads the data in the internally indicated address and verifies the data immediately after the
Write Operation. The Sequential Read operation can be performed with both Current Read and Random Read. With the
Sequential Read Cycle it is possible to continuously read the next data.
・ Random Read operation allows the Master to access any memory location indicated by word address.
・ In cases where the previous operation is Random or Current Read (which includes Sequential Read), the internal
address counter is increased by one from the last accessed address (n). Thus Current Read outputs the data of the
next word address (n+1).
・ If an Acknowledge is detected and no STOP condition is generated by the Master (μ-COM), the device will continue to
transmit data. (It can transmit all data (2kbit 256word))
・ If an Acknowledge is not detected, the device will terminate further data transmissions and await a STOP condition
before returning to standby mode.
・ If an Acknowledge is detected with the "Low" level (not "High" level), the command will become Sequential Read, and
the next data will be transmitted. Therefore, the Read command is not terminated. In order to terminate Read input
Acknowledge with "High" always, then input a STOP condition.
It is necessary to input
“High” at last ACK timing.
A1A2 D71100
R
E
A
D
S
T
A
R
T
R
/
W
S
T
O
P
DAT
A
SDA
LINE
SLAVE
ADDRESS
A0 D0
A
C
K
A
C
K
Fig.36 Current Read Cycle Timing
It is necessary to input
“High” at last ACK timing.
Fig.37 Sequential Read Cycle Timing （With Current Read）
Fig.35 Random Read Cycle Timing
W
R
I
T
E
S
T
A
R
T
R
/
W
A
C
K
S
T
O
P
WORD
ADDRESS(n)
SDA
LINE
A
C
K
A
C
K
DATA(n)
A
C
K
SLAVE
ADDRESS
10 01A0A1A2 WA
7A0 D0
SLAVE
ADDRESS
10 0
1A1A2
S
T
A
R
T
D7
R
/
W
R
E
A
D
WA
0
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
10 0
1A0A1A2 D0D7 D0D7
It is necessary to
input “High” at
last ACK timing.
11/19
●Write Protect Cycle
・Permanent set Write Protect command set data of 00h～7Fh in 256 words write protection block. Clear Write Protect
command can cancel write protection block which is set by set write Protect command. Cancel of write protection
block which is set by permanent set Write Protect command at once is impossibility. When these commands are
carried out, WP pin must be OPEN or GND.
・Permanent Set Write Protect command needs tWR from stop condition same as Byete Write and Page Write,
During tWR, input command is canceled.
・Refer to P8/19 about reply of ACK in each protect state.
・Permanent set Write Protect command set data of 00h～7Fh in 256 words write protection block. Clear Write Protect
command can cancel write protection block which is set by set write Protect command. Cancel of write protection
block which is set by permanent set Write Protect command at once is impossibility. When these commands are
carried out, WP pin must be OPEN or GND.
・Permanent Set Protect command needs tWR from stop condition same as Byete Write and Page Write, During tWR,
input command is canceled.
・Refer to P8/19 about reply of ACk in each protect state.
W
R
I
T
E
S
T
A
R
T
R
/
W
A
C
K
S
T
O
P
WORD
ADDRESS
SDA
LINE
A
C
K
DATA
A
C
K
SLAVE
ADDRESS
10 0
1A0 A1 A2 * ** *
WP
*:DON’T CARE
W
R
I
T
E
S
T
A
R
T
R
/
W
A
C
K
S
T
O
P
WORD
ADDRESS
SDA
LINE
A
C
K
DATA
A
C
K
SLAVE
ADDRESS
100 11 0 0 * ** *
WP
*:DON’T CARE
Fig. 38 Permanent Write Protect Cycle
Fi
. 39 Set Write Protect C
cle
12/19
・Clear Write Protect command can cancel write protection block which is set by set write Protect command. Cancel
of write protection block which is set by permanent set Write Protect command at once is impossibility. When these
commands are carried out, WP pin must be OPEN or GND.
・Permanent Clear Write Protect command needs tWR from stop condition same as Byete Write and Page Write,
During tWR, input command is canceled.
・Refer to P8/19 about reply of ACk in each protect state.
●Software Reset
Execute software reset in the event that the device is in an unexpected state after power up and/or the command input
needs to be reset. Below are three types（Fig.39 –(a), (b), (c)） of software reset:
During dummy clock, release the SDA BUS (tied to VCC by a pull-up resistor). During this time the device may pull the SDA
line Low for Acknowledge or the outputting of read data.If the Master sets the SDA line to High, it will conflict with the
device output Low, which can cause current overload and result in instantaneous power down, which may damage the
device.
1 2 13
14
SCL
DUMMY CLOCK×14 START×2
SCL
SCL
Fig.39-(a) DUMMY CLOCK×14 + START+START
1 2 3 8 9
7
Fig.39-(c) START×9
* COMMAND starts with start condition.
2
1 8 9
DUMMY CLOCK×9START
Fig.39-(b) START + DUMMY CLOCK×9 + START
START
COMMAND
COMMAND
COMMAND
COMMAND
COMMAND
COMMAND
START×9
SDA
SDA
SDA
W
R
I
T
E
S
T
A
R
T
R
/
W
A
C
K
S
T
O
P
WORD
ADDRESS
SDA
LINE
A
C
K
DATA
A
C
K
SLAVE
ADDRESS
100 11 1 0 * ** *
WP
*:DON’T CARE
Fi
g
. 40 Clear Write Protect C
y
cle
13/19
AN ENLARGEMENT
・The rising edge
・of SDA
WP cancellation
effective period
SLAVE
ADDRESS
SLAVE
ADDRESS
WRITE COMMAND
SLAVE DATA
ADDRESS
WORD
ADDRESS
SLAVE
ADDRESS
S
T
A
R
T
S
Ｔ
O
P
A
C
K
H
S
T
A
R
T
S
T
A
R
T
A
C
K
H
S
T
A
R
T
A
C
K
H
S
T
A
R
T
A
C
K
L
A
C
K
L
A
C
K
L
S
Ｔ
O
P
After the internal write cycle
is completed, ACK will be returned
(ACK=Low). Then input next
Word Address and data.
During the internal write cycle,
no ACK will be returned.
(ACK=High)
・・・
●Acknowledge polling
Since the IC ignores all input commands during the internal write cycle, no ACK signal will be returned.
When the Master sends the next command after the Write command, if the device returns an ACK signal it means that the
program is completed. No ACK signal indicates that the device is still busy.
Using Acknowledge polling decreases the waiting time by tWR=5ms.
When operating Write or Current Read after Write, first transmit the Slave address (R/W is"High" or "Low"). After the
device returns the ACK signal continue word address input or data output.
●WP effective timing
WP is normally fixed at "H" or "L". However, in case WP needs to be controlled in order to cancel the Write command, pay
attention to “WP effective timing” as follows:
The Write command is canceled by setting WP to "H" within the WP cancellation effective period.
The period from the START condition to the rising edge of the clock (which takes in the data DO - the first byte of the Page
Write data) is the ‘invalid cancellation period’. WP input is considered inconsequential during this period. The setup time
for the rising edge of the SCL, which takes in DO, must be more than 100ns.
The period from the rising edge of SCL (which takes in the data D0) to the end of internal write cycle (tWR) is the ‘effective
cancellation period’. When WP is set to "H" during tWR, Write operation is stopped, making it necessary to rewrite the
data.
It is not necessary to wait for tWR (5ms max.) after stopping the Write command by WP because the device is in standby
mode.
・The rising edge of the clock
which take in D0
SCL
D0 ACK
AN ENLARGEMENT
SCL
SDA ACK
D0
SDA
WP
WP cancellation
invalid period
Data is not
guaranteed
No data will be written
Stop of the write
operation
Fig.41 WP effective 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
THE FIRST WRITE COMMAND
tWR
THE SECOND WRITE COMMAND
・・・
tWR
Fig.40 Successive Write Operation By Acknowledge Polling
14/19
Microcontroller
THE CAPACITANCE
OF BUS LINE (CBUS)
Fig.43 I/O Circuit
●Command cancellation from the START and STOP conditions
Command input is canceled by successive inputs of START and STOP conditions. (Refer to Fig.42)
However, during ACK or data output, the device may set the SDA line to Low, making operation of the START and STOP
conditions impossible, and thus preventing reset. In this case execute reset by software. (Refer to Fig.39)
The internal address counter will not be determined when operating the Cancel command by the START and STOP
conditions during Random, Sequential or Current Read. Operate a Random Read in this case.
●I/O Circuit
○SDA Pin Pull-up Resistor
A pull-up resistor is required because SDA is an NMOS open drain. Determine the resistor value of (RPU) by considering
the VIL and IL, and VOL-IOL characteristics. If a large RPU is chosen, the clock frequency needs to be slow. A smaller
RPU will result in a larger operating current.
○Maximum RPU
The maximum of RPU can be determined by the following factors.
①The SDA rise time determined by RPU and the capacitance of the BUS line(CBUS) must be less than tR.
In addition, all other timings must be kept within the AC specifications.
②When the SDA BUS is High, the voltage A at the SDA BUS is determined from the total input leakage(IL) of all devices
connected to the BUS. RPU must be higher than the input High level of the microcontroller and the device, including a
noise margin 0.2VCC.
VCC-ILRPU-0.2 VCC ≧ VIH
∴RPU ≦0.8VCC-VIH
IL
Examples: When VCC =3V, IL=10μA, VIH=0.7 VCC
According to ②
≦300 ［kΩ］
RPU ≦0.8×3-0.7×3
10×10-6
Fig.42 Command cancellation by the START and STOP conditions during input of the Slave Address
SCL
SDA 1 1
0 0
START
CONDITION
STOP
CONDITION
RPU
A
BR34E02
SDA PIN
IL IL
15/19
Fig.45 Input/Output Collision Timing
○ Minimum RPU
The minimum value of RPU is determined by following factors.
①Meets the condition that VOLMAX=0.4V, IOLMAX=3mA when the output is Low.
②VOLMAX=0.4V must be lower than the input Low level of the microcontroller and the EEPROM
including the recommended noise margin of 0.1VCC.
VOLMAX ≦ VIL-0.1 VCC
Examples: VCC=3V, VOL=0.4V, IOL=3mA, the VIL of the controller and the EEPROM is VIL=0.3VCC,
and VOL=0.4［V］
And VIL=0.3×3
=0.9［V］
so that condition ② is met
○SCL Pin Pull-up Resistor
When SCL is controlled by the CMOS output the pull-up resistor at SCL is not required.
However, should SCL be set to Hi-Z, connection of a pull-up resistor between SCL and VCC is recommended.
Several kΩ are recommended for the pull-up resistor in order to drive the output port of the microcontroller.
●A0, A1, A2, WP Pin connections
○ Device Address Pin (A0, A1, A2) connections
The status of the device address pins is compared with the device address sent by the Master. One of the devices that is
connected to the identical BUS is selected. Pull up or down these pins or connect them to VCC or GND. Pins that are not
used as device address (N.C.Pins) may be High, Low, or Hi-Z.
○ WP Pin connection
The WP input allows or prohibits write operations. When WP is High, only Read is available and Write to all address is
prohibited. Both Read and Write are available when WP is Low.
In the event that the device is used as a ROM, it is recommended that the WP input be pulled up or connected to VCC.
When both READ and WRITE are operated, the WP input must be pulled down or connected to GND or controlled.
●Microcontroller connection
○Concerning Rs
The open drain interface is recommended for the SDA port in the I2C BUS. However, if the Tri-state CMOS interface is
applied to SDA, insert a series resistor (Rs) between the SDA pin of the device and the pull up resistor RPU is
recommended, since it will serve to limit the current between the PMOS of the microcontroller, and the NMOS of the
EEPROM. Rs also protects the SDA pin from surges. Therefore, Rs is able to be used though open drain inout of the
SDA port.
≧867 ［Ω］
RPU ≧3-0.4
3×10 -3
According to ①
A
CK
“L” OUTPUT OF EEPROM
'H'OUTPUT OF
CONTROLLER
The “H” output of controller and the “L” output of
EEPROM may cause current overload to SDA line.
SCL
SDA
∴
VCC-VOL
RPU ≦IOL
RPU ≧VCC-VOL
IOL
RPU
CONTROLLER
RS
EEPROM
Fig.44 I/O Circuit
16/19
Vcc
R
S
Vcc
I
≧300［Ω］
∴
RS≧3
10×10-3
Examples: When VCC=3V, I=10mA
≦I
RS≧
CONTROLLER EEPROM
"L" OUTPUT
RS
RPU
"H" OUTPUT
MAXIMUM
CURRENT
○ Rs Maximum
The maximum value of Rs is determined by following factors.
①SDA rise time determined by RPU and the capacitance value of the BUS line (CBUS) of SDA must be less than tR. In
addition, the other timings must be within the timing conditions of the AC.
②When the output from SDA is Low, the voltage of the BUS at A is determined by RPU, and Rs must be lower than
the input Low level of the microcontroller, including recommended noise margin (0.1VCC).
○ Rs Minimum
The minimum value of Rs is determined by the current overload during BUS conflict.
Current overload may cause noises in the power line and instantaneous power down.
The following conditions must be met, where “I” is the maximum permissible current, which depends on the Vcc line
impedance as well as other factors. “I” current must be less than 10mA for EEPROM.
≦
RPU
∴
VOL+0.1VCC≦VIL
(VCC-VOL)×RS+
RS≦
1.67［kΩ］
RPU+RS
≦×
VIL-VOL-0.1VCC
1.1VCC-VIL
1.1×3-0.3×3
×
0.3×3-0.4-0.1×3
According to ②RS
Examples : When VCC=3V　VIL=0.3VCC　VOL=0.4V　RPU=20kΩ
20×103
RPU
CONTROLLER
RS
EEPROM
IOL
A
BUS
CAPACITANCE
VOL
VCC
VIL
Fig.46 I/O Circuit
Fig.47 I/O Circuit
17/19
●I2C BUS Input / Output equivalent circuits
○Input (A0,A2,SCL)
○Input / Output (SDA)
○Input (A1)
○Input (WP)
Fig.48 Input Pin Circuit
Fig.50 Input Pin Circuit
Fig.49 Input / Output Pin Circuit
Fig.51 Input Pin Circuit
18/19
●Power Supply Notes
VCC increases through the low voltage region where the internal circuit of IC and the microcontroller are unstable. In order
to prevent malfunction, the IC has P.O.R and LVCC functionality. During power up, ensure that the following conditions are
met to guaranty P.O.R. and LVCC operability.
1. "SDA='H'" and "SCL='L' or 'H'".
2. Follow the recommended conditions of tR, tOFF, Vbot so that P.O.R. will be activated during power up.
tOFF
tR
Vbot
0
Fig.52 VCC rising wavefrom
VCC
tR tOFF Vbot
Below 10ms Above 10ms Below 0.3V
Below 100ms Above 10ms Below 0.2V
Recommended conditions of tR, tOFF, Vbot
3. Prevent SDA and SCL from being "Hi-Z".
In case that condition 1. and/or 2. cannot be met, take following actions.
A） If unable to keep Condition 1 (SDA is "Low" during power up)
→Make sure that SDA and SCL are "High" as in the figure below.
tLOW
tSU:DAT
tDH
A
fter Vcc becomes stable
SCL
VCC
SDA
Fig.53 SCL="H" and SDA="L"
tSU:DAT
A
fter Vcc becomes stable
Fig.54 SCL="L" and SDA="L"
B） If unable to keep Condition 2
→After the power stabilizes, execute software reset. (See page 9,10)
C） If unable to keep either Condition 1 or 2
→Follow Instruction A first, then B
●LVCC Circuit
The LVCC circuit prevents Write operation at low voltage and prevents inadvertent writing. A voltage below the LVCC
voltage (1.2V typ.) prohibits Write operation.
●VCC Noise
○Bypass Capacitor
Noise and surges on the power line may cause abnormal function. It is recommended that bypass capacitors (0.1μF) be
attached between VCC and GND externally.
●Cautions On Use
1) Descrived numeric values and data are design representative values, and the values are not guaranteed.
2) We believe that application circuit examples are recommendable, however, in actual use, confirm characteristics
further sufficiently. In the case of use by changing the fixed number of external parts, make your decision with
sufficient margin in consideration of static characteristics and transition characteristics and fluctuations of external
parts and our LSI.
3) Absolute maximum ratings
If the absolute maximum ratings such as impressed voltage and action temperature range and so forth are exceeded,
LSI may be destructed. Do not impress voltage and temperature exceeding the absolute maximum ratings. In the case
of fear exceeding the absolute maximum ratings, take physical safety countermeasures such as fuses, and see to it
that conditions exceeding the absolute maximum ratings should not be impressed to LSI.
4) GND electric potential
Set the voltage of GND terminal lowest at any action condition. Make sure that each terminal voltage is lower than that
of GND terminal.
5) Heat design
In consideration of permissible dissipation in actual use condition, carry out heat design with sufficient margin.
6) Terminal to terminal short circuit and wrong packaging
When to package LSI on to a board, pay sufficient attention to LSI direction and displacement. Wrong packaging
may destruct LSI. And in the case of short circuit between LSI terminals and terminals and power source,
terminal and GND owing to foreign matter, LSI may be destructed.
7) Use in a strong electromagnetic field may cause malfunction, therfore, evaluate design sufficiently.
19/19
Package type
FVT:TSSOP-B8
NUX:VSON008X2030
E2:reel shape emboss taping
TR: reel shape emboss taping
B
02=2K
R 3 4 E 0 2 W E 2 F V T
●Selection of order type
●Package Specifications
（Unit:mm)
<Dimensions> <Tape and Reel Information>
Tape
Quantity
Direction
of feed
Embossed carer tape
2500pcs
E2
(Pin 1is at the upper left when holding the reel with the left hand while
pulling the tape out towards the right)
Reel
Direction of feed
Pin 1
1234
1234
1234
1234
1234
1234
1234
1234
※Please order in multiples of the minimum quantity
Catalog No.05T325Be '05.10 ROHM C 1000 TSU
ROHM type BUS type Product type Capacity Double Cell Package specifications
5
4
8
1
0.1
6.4±0.3
4.4
±
0.2
3.0±0.2
0.22±0.1
1.15±0.1
0.65
(0.52)
0.15±0.1
0.3Min.
0.1
VSON008X2030
Tape
Quantity
Direction
of feed
Embossed carrier tape
4000pcs
(The direction is the 1pin of product is at the upper light when you hold
reel on the left hand and you pull out the tape on the right hand)
<Tape and Reel information>
TR
※When you order , please order in times the amount of package quantity.
(Unit:mm)
<Dimension>
Reel
Direction of feed
1Pin
TSSOP-B8
Notes
No technical content pages of this document may be reproduced in any form or transmitted by any
means without prior permission of ROHM CO.,LTD.
The contents described herein are subject to change without notice. The specifications for the
product described in this document are for reference only. Upon actual use, therefore, please request
that specifications to be separately delivered.
Application circuit diagrams and circuit constants contained herein are shown as examples of standard
use and operation. Please pay careful attention to the peripheral conditions when designing circuits
and deciding upon circuit constants in the set.
Any data, including, but not limited to application circuit diagrams information, described herein
are intended only as illustrations of such devices and not as the specifications for such devices. ROHM
CO.,LTD. disclaims any warranty that any use of such devices shall be free from infringement of any
third party's intellectual property rights or other proprietary rights, and further, assumes no liability of
whatsoever nature in the event of any such infringement, or arising from or connected with or related
to the use of such devices.
Upon the sale of any such devices, other than for buyer's right to use such devices itself, resell or
otherwise dispose of the same, no express or implied right or license to practice or commercially
exploit any intellectual property rights or other proprietary rights owned or controlled by
ROHM CO., LTD. is granted to any such buyer.
Products listed in this document are no antiradiation design.
Appendix1-Rev2.0
Thank you for your accessing to ROHM product informations.
More detail product informations and catalogs are available, please contact your nearest sales office.
ROHM Customer Support System THE AMERICAS / EUPOPE / ASIA / JAPAN
Contact us : webmaster@ rohm.co.jp
www.rohm.com
Copyright © 2007 ROHM CO.,LTD.
The products listed in this document are designed to be used with ordinary electronic equipment or devices
(such as audio visual equipment, office-automation equipment, communications devices, electrical
appliances and electronic toys).
Should you intend to use these products with equipment or devices which require an extremely high level
of reliability and the malfunction of which would directly endanger human life (such as medical
instruments, transportation equipment, aerospace machinery, nuclear-reactor controllers, fuel controllers
and other safety devices), please be sure to consult with our sales representative in advance.
It is our top priority to supply products with the utmost quality and reliability. However, there is always a chance
of failure due to unexpected factors. Therefore, please take into account the derating characteristics and allow
for sufficient safety features, such as extra margin, anti-flammability, and fail-safe measures when designing in
order to prevent possible accidents that may result in bodily harm or fire caused by component failure. ROHM
cannot be held responsible for any damages arising from the use of the products under conditions out of the
range of the specifications or due to non-compliance with the NOTES specified in this catalog.
21, Saiin Mizosaki-cho, Ukyo-ku, Kyoto 615-8585, Japan TEL : +81-75-311-2121
FAX : +81-75-315-0172
Appendix