POWER SOURCE CONTROL CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide an inexpensive power source control circuit which reduces the power consumption of an electronic device by lowering the source voltage while ensuring the normal operation of the electronic device. SOLUTION: This circuit is equipped with a switching means 10 which switches the output voltage Vo of a constant voltage circuit 1 and a decision means 13 which decides at least one of the operation state of the CPU of the electronic device and the connection state of external devices 16 and 17 and the switching means 10 switches the output voltage of the constant voltage circuit 1 according to the output of the decision means 13. In light load mode wherein the electronic device is used alone or the CPU of the electronic device is in key input operation, the source voltage is lowered to reduce the power consumption.