BU9889GUL-W Rohm, BU9889GUL-W Datasheet - Page 13

• Manufacturer Part Number: BU9889GUL-W
• Description: WL-CSP EEPROM family I2C BUS
• Manufacturer: Rohm

●I/O peripheral circuit
●A2, WP process
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BU9889GUL-W
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○Pull up resistance of SDA terminal
○Maximum value of R
○Minimum value of R
○Pull up resistance of SCL terminal
○Process of device address terminals (A2)
○Process of WP terminal
SDA is NMOS open drain, so requires pull up resistance. As for this resistance value (R
this resistance value from microcontroller V
limited. The smaller the R
The maximum value of R
(1)SDA rise time to be determined by the capacitance (CBUS) of bus line of R
(2)The bus electric potential ○
The minimum value of R
(1)When IC outputs LOW, it should be satisfied that V
(2)V
When SCL control is made at CMOS output port, there is no need, but in the case there is timing where SCL becomes
'Hi-Z', add a pull up resistance. As for the pull up resistance, one of several kΩ ~ several ten kΩ is recommended in
consideration of drive performance of output port of microcontroller.
Check whether the set device address coincides with device address input sent from the master side or not, and select
one among plural devices connected to a same bus. Connect this terminal to pull up or pull down, or Vcc or GND.
WP terminal is the terminal that prohibits and permits write in hardware manner. In 'H' status, only READ is available and
WRITE of all address is prohibited. In the case of 'L', both are available. In the case of use it as an ROM, it is
recommended to connect it to pull up or Vcc. In the case to use both READ and WRITE, control WP terminal or connect it
to pull down or GND.
Vcc - I
Ex.) When Vcc = 3V, I
And AC timing should be satisfied even when SDA rise time is late.
bus and R
noise margin 0.2Vcc.
margin 0.1Vcc.
Ex.) When Vcc= 3V, V
from(1),
And
Therefore, the condition (2) is satisfied.
∴
∴
OLMAX
R
V
PU
OLMAX
V
R
CC
L
R
=0.4V should secure the input 'L' level (V
R
PU
R
≦
≦
PU
PU
－V
PU
≦ V
PU
- 0.2Vcc ≧ V
0.8×3－0.7×3
300 ［kΩ］
≧
R
OL
≦
should sufficiently secure the input 'H' level (V
PU
10×10
IL
≦ I
V
-0.1 Vcc
0.8V
CC
PU
PU
≧
≧ 867 ［Ω］
I
OL
－V
OL
-6
CC
L
V
PU
OL
I
=10μA, V
PU
3－0.4
V
L
PU
OL
OL
3×10
－ V
0.4V, I
IL
is determined by the following factors.
=0.9［V］
, the larger the consumption current at action.
=0.4［V］
is determined by the following factors.
=0.3×3
IH
IH
A
-3
to be determined by input leak total (I
OL
IH
=3mA, microcontroller, EEPROM V
= 0.7Vcc, from (2)
IL
, I
L
, and V
IL
) of microcontroller and EEPROM including recommended noise
OLMAX
13/17
OL
-I
OL
=0.4V and I
characteristics of this IC. If R
IH
Microcontroller
) of microcontroller and EEPROM including recommended
IL
L
OLMAX
) of device connected to bus output of 'H' to SDA
=0.3Vcc
=3mA.
Fig.42 I/O circuit diagram
PU
IL
and SDA should be tR or below.
PU
), select an appropriate value to
R
PU
PU
Bus line
Capacity
CBUS
is large, action frequency is
A
IL
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2010.01 - Rev.A
Technical Note
SDA terminal
BR9889GUL-W