| 摘要 |
PROBLEM TO BE SOLVED: To provide a constant voltage circuit operating for maintaining an output voltage from it to be constant, even when a reference voltage outputted from a reference voltage generation circuit fluctuates due to the fluctuation of a power voltage variable by a communication distance and a communication environment. SOLUTION: In this constant voltage circuit, having a transistor for controlling an output voltage, an amplifier, a resistor part, and a reference voltage generation circuit, a switch is arranged between an inverting input terminal or a non-inverting input terminal of the amplifier and the reference voltage generation circuit. When the power voltage is lowered, the switch is turned off; when the poser voltage is constant, the switch is turned on. COPYRIGHT: (C)2008,JPO&INPIT
|
