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HMS87C1X04B/08B/16B
72
SEP. 2004 Ver 1.03
Figure 18-7 Application Example of Unused Input Port
Figure 18-8 Application Example of Unused Output Port
INPUT PIN
VDD
GND
i
VDD
X
Weak pull-up current flows
VDD
internal
pull-up
INPUT PIN
i
VDD
X
Very weak current flows
VDD
O
O
OPEN
OPEN
i=0
O
i=0
O
GND
When port is configure as an input, input level should
be closed to 0V or 5V to avoid power consumption.
OUTPUT PIN
GND
i
In the left case, much current flows from port to GND.
X
ON
OFF
OUTPUT PIN
GND
i
In the left case, Tr. base current flows from port to GND.
i=0
X
OFF
ON
VDD
L
ON
OFF
OPEN
GND
VDD
L
ON
OFF
To avoid power consumption, there should be low output
ON
OFF
O
O
VDD
O
to the port.