Semiconductor integrated circuit having internal power supply voltage down conversion circuit

摘要

In an oscillation detection circuit an internal voltage is compared with an oscillation detection level corresponding to a reference voltage plus a predetermined variation and when a voltage having a level higher than the oscillation detection level is observed a predetermined number of times within a predetermined period of time a decision is made that the internal voltage is in oscillation and an oscillation detection signal having the high level is output. In the internal power supply voltage down conversion circuit when a p-channel MOS transistor receives the oscillation detection signal of the high level the transistor turns off to interrupt a current supplied from a drive transistor to an internal power supply node.