POWER SUPPLY VOLTAGE DETECTING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To detect the voltage level of low-voltage power, without increasing power consumption in a semiconductor device having at lest two power supply voltages different in voltage levels. SOLUTION: The input part of a CMOS inverter 803 is connected to a low voltage power source 801, and CMOS inverter output corresponding to the voltage level of the low voltage power source 801 is outputted. Thus, the voltage level of low voltage power source 801 is detected. The operating voltage supply part of the CMOS inverter 803 is connected to a high voltage power source 802 through voltage drop means 806 and 807, so that the voltage of the level lower than the voltage level of the high voltage power source 802 is supplied.