mb90f352espmc1 Fujitsu Microelectronics, Inc., mb90f352espmc1 Datasheet - Page 24

• Manufacturer Part Number: mb90f352espmc1
• Description: 16-bit Proprietary Microcontrollers
• Manufacturer: Fujitsu Microelectronics, Inc.

24
MB90350E Series
I HANDLING DEVICES
1. Preventing latch-up
2. Treatment of unused pins
3. Using external clock
4. Precautions for when not using a sub clock signal
5. Notes on during operation of PLL clock mode
CMOS IC chips may suffer latch-up under the following conditions :
• A voltage higher than V
• A voltage higher than the rated voltage is applied between V
• The AV
Latch-up may increase the power supply current drastically, causing thermal damage to the device.
For the same reason, also be careful not to let the analog power-supply voltage (AV
power-supply voltage (V
Leaving unused input pins open may result in misbehavior or latch up and possible permanent damage of the
device. Therefore they must be pulled up or pulled down through resistors. In this case those resistors should
be more than 2 kΩ.
Unused I/O pins should be set to the output state and can be left open, or the input state with the above described
connection.
To use external clock, drive the X0 pin and leave X1 pin open.
X0A and X1A are oscillation pins for sub clock. If you do not connect pins X0A and X1A to an oscillator, use
pull-down handling on the X0A pin, and leave the X1A pin open.
On this microcontroller, if in case the crystal oscillator breaks off or an external reference clock input stops while
the PLL clock mode is selected, a self-oscillator circuit contained in the PLL may continue its operation at its
self-running frequency. However, Fujitsu will not guarantee results of operations if such failure occurs.
CC
power supply is applied before the V
CC
CC
) .
or lower than V
SS
is applied to an input or output pin.
CC
voltage.
Open
CC
and V
X0
X1
SS
MB90350E Series
pins.
CC
, AVRH) exceed the digital