MB89663 datasheet(11/48 Pages) FUJITSU

11 / 48 page

MB89660 Series

s 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- or high-voltage pins or if higher than the voltage which shows on “1. Absolute Maximum

Ratings” in section “ s Electrical Characteristics” is applied between VCC and 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 Converters

Connect to be AVCC = VCC and AVSS = AVR = VSS if the A/D converters are not in use.

4. 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.

5. 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.

MB89663 Datasheet(PDF) 11 Page - fujitsu semiconductor