MB2146-301A Fujitsu Microelectronics, Inc., MB2146-301A Datasheet - Page 14

• Manufacturer Part Number: MB2146-301A
• Description: 8-bit Microcontrollers
• Manufacturer: Fujitsu Microelectronics, Inc.

14
MB95130MB Series
■ HANDLING DEVICES
• Preventing latch-up
• Stable supply voltage
• Precautions for use of external clock
PIN CONNECTION
• Treatment of unused pins
• Treatment of power supply pins on A/D converter
• Power Supply Pins
• Mode pin (MOD)
Care must be taken to ensure that maximum voltage ratings are not exceeded when the devices are used.
Latch-up may occur on CMOS ICs if voltage higher than V
other than medium- and high-withstand voltage pins or if voltage higher than the rating voltage is applied between
V
When latch-up occurs, power supply current increases rapidly and might thermally damage elements.
Also, take care to prevent the analog power supply voltage (AV
For stabilization, in principle, keep the variation in V
(50 / 60 Hz) not to exceed 10% of the standard V
variation rate does not exceed 0.1 V/ms during a momentary change such as when the power supply is switched.
Even when an external clock is used, oscillation stabilization wait time is required for power-on reset, wake-up
from the sub clock mode or stop mode.
Leaving unused input pins unconnected can cause abnormal operation or latch-up, leading to permanent
damage. Unused input pins should always be pulled up or down through resistance of at least 2 kΩ.
Any unused input/output pins may be set to the output mode and left open, or set to the input mode and treated
the same as unused input pins. If there is any unused output pin, make it open.
Connect to be AV
Noise riding on the AV
as a bypass capacitor between AV
In products with multiple V
to avoid abnormal operations including latch-up. However, all the pins must be connected to external power
supply and a ground line to lower the electro-magnetic emission level, to prevent abnormal operation of strobe
signals caused by the rise in the ground level, and to conform to the total output current rating. Moreover, connect
the current supply source with the V
To prevent the device unintentionally entering the test mode due to noise, lay out the printed circuit board so as
to minimize the distance from the mode pins to V
digital power supply voltage (V
Supply voltage should be stabilized.
A sudden change in power supply voltage may cause a malfunction even within the guaranteed operating range
of the V
It is also advisable to connect a ceramic bypass capacitor of approximately 0.1 µF between V
near this device.
Connect the mode pin directly to V
CC
pin and V
CC
power supply voltage.
SS
pin.
CC
= V
CC
CC
pin may cause accuracy degradation. So, connect approx. 0.1 µF ceramic capacitor
and AV
CC
or V
CC
) when the analog system power supply is turned on or off.
SS
SS
CC
CC
= V
pins, the pins of the same potential are internally connected in the device
CC
and AV
or V
and V
SS
SS
even if the A/D converter is not in use.
pins.
SS
SS
pins in the vicinity of this device.
pins of this device at the low impedance.
CC
CC
value and suppress the voltage variation so that the transient
CC
or V
ripple (p-p value) in a commercial frequency range
SS
CC
pins and to provide a low-impedance connection.
or lower than V
CC
) and analog input voltage from exceeding the
SS
is applied to input and output pins
CC
and V
SS
pins