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5
KX-NT305X / KX-NT305X-B
4.2.
Circuit Operations
4.2.1.
LED Circuit and KEY Input Circuit
Circuit Operation:
A drive pulse wave, as in Fig.1, is output by IC1. That signal goes through the drive digital transistor and connects the key button
and LED cathode. By pressing the key, the drive pulse wave is input to Pin20-Pin24 and Pin28-Pin32.
In order to light the appropriate LED, the LED control port is turned ON. That result LED is lit by the pulse Driver.
A drive pulse wave, as in Fig.1, is output by IC1. That signal goes through the drive digital transistor and connects the key button
and LED cathode. By pressing the key, the drive pulse wave is input to Pin20-Pin24 and Pin28-Pin32.
In order to light the appropriate LED, the LED control port is turned ON. That result LED is lit by the pulse Driver.
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