MB89580B View Datasheet(PDF) - Fujitsu

Part Name

Description

Manufacturer

MB89580B

8-bit Proprietary Microcontrollers

Fujitsu 

MB89580B/580BW 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 or output pins

other than the medium- and high-voltage pins or if voltage higher than the rating 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 input from exceeding the digital power supply (Vcc) when the power supply

to the analog power system is turned on and off.

2. Treatment of Unused Input Pins

Leaving unused input pins open could cause malfunctions and latchup leading to permanent damage to the

pins. These unused pins should be connected to a pullup or pulldown resistance of at least 2 kΩ between the

pin and the power supply.

Unused I/O pins should be placed in output state to leave it open or pins that are in input state should be handled

the same as unused input pins.

3. 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.

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