| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an internal power supply circuit for generating a stable internal power supply voltage. <P>SOLUTION: In a voltage detection part 10, whether an external power supply voltage VCC is higher or lower than a predetermined voltage is detected, and a detecting signal DET which is its result is applied to a voltage switching part 30. On the other hand, in constant voltage generation parts 20a, 20b constituted of similar circuits, different constant voltages 20a, 20b are generated from the external power supply voltage VCC, and outputted to the voltage switching part 30. In the voltage switching part 30, one of the constant voltages 20a, 20b is selected based on the detecting signal DET, and applied as a reference voltage VRF to an internal power supply output part 40. In the internal power supply output part 40, an internal power supply voltage VDD is generated from the external power supply voltage VCC according to the reference voltage VRF and outputted. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
