BR93L66RF-WE2 Rohm Semiconductor, BR93L66RF-WE2 Datasheet - Page 32

• Manufacturer Part Number: BR93L66RF-WE2
• Description: IC EEPROM 4KBIT 2MHZ 8SOP
• Manufacturer: Rohm Semiconductor

Specifications of BR93L66RF-WE2

• Memory Size: 4K (256 x 16)
• Format - Memory: EEPROMs - Serial
• Memory Type: EEPROM
• Speed: 2MHz
• Interface: Microwire, 3-Wire Serial
• Voltage - Supply: 1.8 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-SOP
• Clock Frequency: 2MHz
• Supply Voltage Range: 1.8V To 5.5V
• Memory Case Style: SOP
• No. Of Pins: 8
• Operating Temperature Range: -40°C To +85°C
• Svhc: No SVHC (18-Jun-2010)
• Package /: RoHS Compliant
• Memory Configuration: 256 X 16
• Interface Type: Serial, Microwire
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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BR93L□□-W Series, 93A□□-WM Series, BR93H□□-WC Series
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3-2) DO is available in both pull up and pull down.
○Pull up resistance Rpu and pull down resistance Rpd of DO pin
As for pull up and pull down resistance value, select an appropriate value to this resistance value from microcontroller
VIH, VIL, and VOH, IOH, VOL, IOL characteristics of this IC.
Microcontroller
Microcontroller
Do output become “High-Z” in other READY / BUSY output timing than after data output at read command and write
command. When malfunction occurs at “High-Z” input of the microcontroller port connected to DO, it is necessary to
pull down and pull up DO. When there is no influence upon the microcontroller actions, DO may be OPEN. If DO is
OPEN, and at timing to output status READY, at timing of CS=“H”, SK=“H”, DI=“H”, EEPROM recognizes thisas a
start bit, resets READY output, and DO=”High-Z”, therefore, READY signal cannot be detected. To avoid such output,
pull up DO pin for improvement.
“L” input
“H” input
VILM
・VOLE
・IOLE
・VILM
Fig.44 DO pull down resistance
VIHM
Fig.43 DO pull up resistance
CS
SK
DI
DO
Rpu
Rpd
High-Z
D0
IOLE
IOHE
Fig.42 READY output timing at DO=OPEN
VOLE
VOHE
“H” output
“L” output
EEPROM
EEPROM
BUSY
READY
Enlarged
With the value of Rpu to satisfy the above equation, VOLE becomes 0.4V or
below, and with VILM(=0.8V), the equation ④ is also satisfied.
With the value of Rpd to satisfy the above equation, VOHE becomes 2.4V or
below, and with VIHM (=3.5V), the equation ⑥ is also satisfied.
32/40
DO
CS
SK
DI
DO
Example) When V
BUSY
BUSY
“H”
Example) When V
∴
∴
Improvement by DO pull up
from the equation ③,
・VOHE
・IOHE
・VIHM
・VOLE
・IOLE
・VILM
READY
High-Z
VOLE ≦ VILM
VOHE ≧ VIHM
VIHM=Vcc×0.7V from the equation ⑤
Rpu ≧
Rpu ≧
Rpu ≧ 2.2 [kΩ]
Rpd ≧
Rpd ≧
Rpd ≧ 48 [kΩ]
CC
=5V, VOLE=0.4V, IOLE=2.1mA, VILM=0.8V,
CC
: EEPROM VOL specifications
: EEPROM IOL specifications
: Microcontroller VIL specifications
: EEPROM VOH specifications
: EEPROM IOH specifications
: Microcontroller VIH specifications
When DO=pull up
When DO=OPEN
Vcc－VOLE
CS=SK=DI=”H”
CS=SK=DI=”H”
=5V, VOHE=Vcc－0.2V, IOHE=0.1mA,
2.1×10
IOLE
0.1×10
5－0.4
VOHE
IOHE
5－0.2
-3
-3
・・・③
・・・④
・・・⑤
・・・⑥
Technical Note
2011.02 - Rev.F