MB89051PFM View Datasheet(PDF) - 3M
Part Name
Description
MFG CO.
'MB89051PFM' PDF : 40 Pages View PDF
MB89051 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. Note to noise in the External Reset Pin (RST)
If the reset pulse applied to the external reset pin (RST) does not meet the specifications, it may cause malfunc-
tions. Use caution so that the reset pulse less than the specifications will not be fed to the external reset pin (RST).
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 Hz 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. Note on the clock during operation
This microcontroller uses a PLL for generating the main clock signal. If the oscillator is removed or the clock
input stops during operation, therefor, the microcontroller may keep on operating at the free-running frequency
of the self-oscillation circuit in the PLL. The operation is not however guaranteed.
6. About port 2 (P20 to P27)
Port 2 serves as an output-only terminal on the emulator.
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