10.5. POWER SUPPLY CIRCUIT
This circuit converts the voltage supplied from PBX into the power supply voltage of +3.3V by
IC6(Switching Regulator IC).
IC10 controls the power supply circuit as below to turn IC6 on in low consumption current at
starting up.
- Input Voltage approx. 30V or less
IC10-pin 1 L
IC6 OFF
- Input Voltage approx. 30V or more
IC10-pin 1 HiZ
IC6ON
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