| 摘要 |
PURPOSE: To provide a semiconductor integrated circuit capable of surely detecting oscillation generated due to the supply of excessive currents in an internal step-down power source circuit, and spontaneously suppressing oscillation by decreasing current supply capability at detecting oscillation. CONSTITUTION: In an oscillation detecting circuit 1, an internal voltage VDL is compared with an oscillation detection level where predetermined fluctuation is added to a reference voltage VREF, and when a voltage level higher than the oscillation detection level is confirmed the predetermined number of times in a fixed period, it is recognized that an oscillating state is set, and an H level oscillation detection signal ODE is outputted. At receiving the H level oscillation detection signal, a P channel MOS transistor 19 of an internal step-down power source circuit is turned off, and current supply from a drive transistor 17 to an internal power supply node 2 is stopped.
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