BR35H320-WC Datasheet, PDF (3/5 Pages) Rohm – Silicon Monolithic Integrated Circuit

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◇NOTES FOR POWER SUPPLY
In order to prevent an inadvertent write, the device has the feature of P.O.R.　
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 CS=“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.
tR
Vcc
◇RECOMMENDED CONDITIONS OF tR, tOFF, Vbot
tR
tOFF
Vbot
tOFF
Vbot
0
Below 10ms Above 10ms
Below 100ms Above 10ms
Below 0.3V
Below 0.2V
Fig.2 Vcc waveform
Please keep CS “H” during power ON/OFF.
The device is an active state during CS is low. The extraordinary function or data collaption may occur because of
noise etc., if power-up is done with CS “L”. In order to prevent above errors from happening, keep CS “H” (=Vcc)
during power ON. (The device does not receive any command during CS is high.)
It may continue at low Vcc by capacitance of Vcc line during power off.
Please keep CS “H” during power off because of the device may make malfunction and inadvertent write.
Ｖｃｃ
Ｖｃｃ
ＧＮＤ
Ｖｃｃ
ＣＳ
ＧＮＤ
Good
Bad
Fig.3　CS TIMING DURING POWER ON/OFF
（Good example）
CS follows Vcc. (CS is pull up to Vcc)
（Bad example）
CS 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.
◇CAUTIONS ON USE
(1) _{Absolute maximum ratings}
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.
(2) _{GND electric potential}
Set the voltage of GND terminal lowest at any action condition. Make sure that each terminal voltages is lower than
that of GND terminal.
(3) _{Heat design}
In consideration of permissible dissipation in actual use condition, carry out heat design with sufficient margin.
(4) _{Terminal to terminal shortcircuit and wrong packaging}
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.
(5) _{Strong electromagnetic field}
Use in a strong electromagnetic field may cause malfunction, therefore, evaluated design sufficiently.
REV. B