| 摘要 |
PROBLEM TO BE SOLVED: To obtain a power supply circuit which can lower the input voltage of a second constant voltage circuit and reduce the power consumption of the second constant voltage circuit to reduce a mounting area thereof. SOLUTION: This power supply circuit comprises a first constant voltage circuit 2 which steps down a power supply voltage VDD from a DC power supply 10 and generates and outputs a prescribed constant voltage V1 and a second constant voltage circuit 3 which steps down the constant voltage V1 outputted by the first constant voltage circuit 2 and generates and outputs a prescribed constant voltage V2. A reference voltage generating circuit 23 in the second constant voltage circuit 3 is made to operate by using the power supply voltage VDD from the DC power supply 10 as its power supply voltage. COPYRIGHT: (C)2003,JPO
|
