| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a constant-voltage circuit, in which increase in a circuit scale is suppressed without output voltage variation due to offset voltage of an error amplifying circuit, in the constant-voltage circuit operating in both a high speed operation mode and a low consumption current mode. <P>SOLUTION: The device is equipped with a reference voltage generating circuit 2 for generating a reference voltage, an output voltage detection circuit (resistors R1, R2) for generating feedback voltage proportional to the output voltage, and an amplifying circuit 6 for operating, at high speed, a differential amplifier circuit 4 in an input stage and an output transistor M1 in an output stage, and the device is equipped with an error amplifying circuit for outputting the voltage according to the voltage difference of the reference voltage and the feedback voltage, and the output transistor M1 for controlling the output voltage on the constant-voltage controlled by the output of the error amplifying circuit. The device is also equipped with a switching signal generating part for generating the switching signal for switching the operation of the constant-voltage circuit between the high speed operation mode or the low current consumption mode and switch means SW1-SW6 for receiving the switching signal for selecting the operation mode from the switching signal generating part and controlling the operation. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
