MB89160/160A Series
■ HANDLING DEVICES
1. Preventing Latchup
Latchup may occur on CMOS ICs if voltage higher than VCC or lower than VSS is applied to input and output pins
other than medium- to high-voltage pins or if higher than the voltage which shows on “ 1. Absolute Maximum
Ratings” in section “■ Electrical Characteristics” is applied between VCC to VSS.
When latchup occurs, power supply current increases rapidly and might thermally damage elements. When
using, take great care not to exceed the absolute maximum ratings.
Also, take care to prevent the analog power supply (AVCC and AVR) and analog input from exceeding the digital
power supply (VCC) when the analog system power supply is turned on and off.
2. Treatment of Unused Input Pins
Leaving unused input pins open could cause malfunctions. They should be connected to a pull-up or pull-down
resistor.
3. Treatment of Power Supply Pins on Microcontrollers with A/D and D/A Converters
Connect to be AVCC = DAVC = VCC and AVSS = AVR = VSS even if the A/D and D/A converters are not in use.
4. Treatment of N.C. Pin
Be sure to leave (internally connected) N.C. pins open.
5. Power Supply Voltage Fluctuations
Although VCC power supply voltage is assured to operate within the rated range, a rapid fluctuation of the voltage
could cause malfunctions, even if it occurs within the rated range. Stabilizing voltage supplied to the IC is
therefore important. As stabilization guidelines, it is recommended to control power so that VCC ripple fluctuations
(P-P value) will be less than 10% of the standard VCC value at the commercial frequency (50 to 60 Hz) and the
transient fluctuation rate will be less than 0.1 V/ms at the time of a momentary fluctuation such as when power
is switched.
6. Precautions when Using an External Clock
Even when an external clock is used, oscillation stabilization time is required for power-on reset (optional) and
wake-up from stop mode.
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