| 摘要 |
PROBLEM TO BE SOLVED: To prevent loss of control information of a control circuit, which is caused by re-executing a power-on reset operation in executing automatic selection for re-selecting a working power supply from a plurality of power supplies in response to a power failure.SOLUTION: A semiconductor integrated circuit 212 includes: a first power supply terminal T1; a second power supply terminal T2; an input voltage selection circuit 2124 that is connected to the terminals T1 and T2; first power switches SW1 and SW2; and a second power switch SW3. The input voltage selection circuit includes: a power-on reset circuit 21244; an input voltage detection circuit 21248; a first variable transmission circuit 2124Y1; a second variable transmission circuit 2124Y2; a voltage comparison/selection circuit 21243; and control circuits 21245 and 21246. In response to a power failure detection result, the control circuit sets the signal transmission amount of a variable transmission circuit, which corresponds to a power switch that has a lower priority out of first and second power switches, out of the first and second variable transmission circuits, so as to make it larger than the signal transmission amount of the other variable transmission circuit. |
