mb90f378 Fujitsu Microelectronics, Inc., mb90f378 Datasheet - Page 16

• Manufacturer Part Number: mb90f378
• Description: 16-bit Proprietary Microcontroller
• Manufacturer: Fujitsu Microelectronics, Inc.

16
MB90378 Series
1. Be sure that the maximum rated voltage is not exceeded (latch-up prevention).
2. Stabilize the supply voltages
3. Power-on
4. Treatment of unused input pins
5. Treatment of A/D converter, and D/A converter power pin
6.
HANDLING DEVICES
A latch-up may occur on a CMOS IC if a voltage higher than V
pin other than medium-to-high voltage pins. A latch-up may also occur if a voltage higher than the rating is
applied between V
result in thermal damage to an element. Take utmost care that the maximum rated voltage is not exceeded.
When turning the power on or off to analog circuits, be sure that the analog supply voltages (AV
analog input voltage do not exceed the digital supply voltage (V
Even within the operation guarantee range of the V
voltage undergoes a rapid change. For voltage stabilization guidelines, the V
at commercial frequencies (50 Hz to 60 Hz) should be suppressed to "10%" or less of the reference V
During a momentary change such as when switching a supply voltage, voltage fluctuations should also be
suppressed so that the "transient fluctuation rate" is 0.1 V/ms or less.
To prevent a malfunction in the built-in voltage drop circuit, secure "50 µs (between 0.2 V and 1.8 V)" or more
for the voltage rise time during power-on.
An unused input pin may cause a malfunction if it is left open. Every unused input pin should be pulled up or down.
When the A/D converter, D/A converter and comparator is not used, connect the pins as follows: AV
AV
When an external clock is used, the oscillation stabilization wait time is required at power-on reset or at cancel-
lation of sub-clock mode or stop mode. As shown in diagram below, when an external clock is used, connect
only the X0 pin and leave the X1 pin open.
Notes on external clock
SS
= AVR = V
SS
.
CC
pin and V
SS
pin. A latch-up causes a rapid increase in the power supply current, which can
Open
CC
supply voltage, a malfunction can be caused if the supply
X0
X1
CC
or lower than V
CC
MB90378 series
).
CC
SS
ripple fluctuations (P-P value)
is applied to an input or output
CC
, AVR) and
CC
CC
value.
= V
CC
,