Large scale integrated circuit for low voltage operation

A semiconductor device comprising:

• a semiconductor chip;
• a plurality of integrated circuit blocks, each of said integrated circuit blocks including a volatile memory formed on said semiconductor chip, each circuit block having two or more operation modes with different consumed currents and at least one of said operation modes is a mode of retaining data in said volatile memory;
• and
• a plurality of voltage converter means, formed on said semiconductor chip, for supplying to said integrated circuit blocks a plurality of internal power supply voltages lower than an input first power supply voltage;
• wherein at least one of the internal power supply voltages, impedances thereof, and consumed currents in said voltage converter means is varied in accordance with one of the operation modes.

A semiconductor device comprising:

• a semiconductor chip;
• a plurality of circuit blocks formed on the semiconductor chip, selectively supplied by a plurality of internal power supply voltages, at least one of the circuit blocks having at least two operation modes with different consumed currents, and at least one circuit block being a volatile memory;
• a reference voltage generator formed on the semiconductor chip, for outputting a reference voltage, comprising a predetermined voltage level for operation of a one of the circuit blocks;
• a plurality of voltage converter means formed on the semiconductor chip for selectively converting an external power supply voltage to a one of the internal power supply voltages by using said reference voltage as the predetermined voltage level;
• and,
• a plurality of switching means for selectively connecting the external power supply voltage to a selected circuit block of the plurality, when the external power supply voltage is smaller than the reference voltage level.