| 摘要 |
<p>PROBLEM TO BE SOLVED: To lighten the load of the software design, the timing design of control signals, etc., in a semiconductor integrated circuit containing a voltage dropper circuit and to reduce the power consumption according to the operation mode. SOLUTION: A contained voltage dropper circuit comprises a first voltage dropper 101 for dropping an external power voltage to a first drop voltage; a second voltage dropper 102 having an output terminal commonly connected to the first voltage dropper circuit, for dropping the external power voltage to a second drop voltage lower than the first drop voltage when being standby active; a first drop voltage judging circuit 201 for judging whether the output voltage of the first voltage dropper circuit exceeds a specified level and outputting the judgment result; and a control circuit 400 which disables the first voltage dropper circuit to provide a high impedance on the output at standby, and enables the first voltage dropper circuit when active to control whether an operation clock is fed to an inner circuit 43, based on an output signal from the first voltage dropper circuit.</p> |
