BR35H128-WC ROHM Co. Ltd., BR35H128-WC Datasheet - Page 3

• Manufacturer Part Number: BR35H128-WC
• Manufacturer: ROHM Co. Ltd.

◇NOTES FOR POWER SUPPLY
Please keep CSB “H” during power ON/OFF.
The device is an active state during CSB is low. The extraordinary function or data collaption may occur because of noise
etc., if power-up is done with CSB “L”. In order to prevent above errors from happening, keep CSB “H” (=Vcc) during power
ON. (The device does not receive any command during CSB is high.)
Please keep CSB “H” during power off because of the device may make malfunction and inadvertent write.
◇CAUTIONS ON USE
Vcc
It may continue at low Vcc by capacitance of Vcc line during power off.
After the power is on, the device is in the write disable mode. P.O.R. works only during power up. The noise may
force the device write enable mode with CSB=“H” during power ON/OFF. In the case of power up, keep the following
conditions to ensure to make the function of P.O.R.
(1) Absolute maximum ratings
(2) GND electric potential
(3) Heat design
(4) Terminal to terminal shortcircuit and wrong packaging
(5) Strong electromagnetic field
In order to prevent an inadvertent write, the device has the feature of P.O.R.
Ｖｃc
ＣＳＢ
0
ＧＮＤ
ＧＮＤ
Ｖｃｃ
Use in a strong electromagnetic field may cause malfunction, therefore, evaluated design sufficiently.
Ｖｃｃ
If the absolute maximum ratings such as impressed voltage and operating 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.
Set the voltage of GND terminal lowest at any action condition. Make sure that each terminal voltages is lower than that
of GND terminal.
When to package LSI onto a board, pay sufficient attention to LSI direction and displacement. Wrong packaging may
destruct LSI. And in the case of shortcircuit between LSI terminals and terminals and power source, terminal and GND
owing to foreign matter, LSI may be destructed.
In consideration of permissible dissipation in actual use condition, carry out heat design with sufficient margin.
Fig.3 CS TIMING DURING POWER ON/OFF
Good
Fig.2 Vcc Waveform
tOFF
Bad
tR
Vbot
◇ RECOMMENDED CONDITIONS OF tR, tOFF, Vbot
（Good example）
（Bad example）
REV. B
CSB follows Vcc. (CSB is pull up to Vcc)
CSB is low during power ON/OFF.
Please take more than 10ms between power ON and power
OFF, or the internal circuit is not always reset.
Below 100ms
Below 10ms
tR
Above 10ms
Above 10ms
tOFF
Below 0.3V
Below 0.2V
Vbot
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