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GENERAL
1-16
1.6 HANDLING DEVICES
(1) Preventing latch-up
Latch-up may occur if a voltage higher than V
CC
or lower than V
SS
is applied to the input or output pins other
than port 40 to 47, or if voltage exceeding the rated value is applied between V
CC
and V
SS
. However, voltages
of up to 7 V can be applied to the P31/INT1 pin irrespective of V
CC
.
When latch-up occurs, the supply current increases rapidly, sometimes resulting in overheating and destruc-
tion. Therefore, no voltage exceeding the maximum ratings should be used.
(2) Handling unused input pins
Leaving unused input pins open may cause a malfunction. Therefore, these pins should be set to pull-up or
pull-down.
(3) Setting internal connection (IC) pin
Always set IC (internal connections) open.
(4) Variations in supply voltage
Although the specified V
CC
supply voltage operating range is assured, a sudden change in the supply voltage
within the specified range may cause a malfunction. Therefore, the voltage supply to the IC should be kept as
constant as possible. The V
CC
ripple (P-P value) at the supply frequency (50 to 60 Hz) should be less than
10% of the typical V
CC
value, or the coefficient of excessive variation should be less than 0.1 V/ms. instanta-
neous change when the power supply is switched.
(5) Precautions for external clocks
It takes some time for oscillation to stabilize after changing the mode to power-on reset (option selection) and
stop. Consequently, an external clock must be input.
(6) Recommended screening conditions
High-temperature aging is recommended for screening before OPTROM-mounted microcontrollers are
mounted.
Program, verify
High-temperature aging
150C
°
, 48H
Read
Mount
•
Writing yield
The test for writing all bits cannot be executed for microcontrollers where the OPTROM microcomputer pro-
gram is not written. Therefore, the 100% writing yield may not be always assured.
(7) Sequence for application of power and analog inputs to A/D converter
Power supplies (AV
CC
and AV
SS
) and analog inputs (AN0 to ANB) to the A/D converter should be turned on
after or at the same time the digital power supply (V
CC
) is turned on.
When the power supplies is turned off, the digital power supply (V
CC
) should be turned off and the power sup-
plies (AV
CC
and AV
SS
) and analog inputs (AN0 to ANB) to the A/D converter are turned off.
Summary of Contents for F2MC-8L Series
Page 121: ...INSTRUCTIONS 4 7 4 5 F2MC 8L FAMILY INSTRUCTION MAP ...
Page 123: ...5 MASK OPTIONS ...
Page 125: ...APPENDIX ...