Patent ID: 6992946

Claim:
A semiconductor device having operation modes of a first mode and a second mode with reduced current consumption relative to that of the first mode, comprising: a main power supply line; a sub power supply line; a first switch circuit connecting said sub power supply line to said main power supply line in said first mode and disconnecting said sub power supply line from said main power supply line in said second mode; and an internal circuit operating according to an input signal in said first mode and entering a standby state in said second mode, said internal circuit including a first field-effect transistor having a gate insulating film with a predetermined thickness and kept in a non-conductive state in said second mode; a second field-effect transistor connected to said main power supply line, having a gate insulating film with a thickness greater than said predetermined thickness and kept in a conductive state in said second mode; and wherein said first mode is a normal mode, said second mode is a power down mode, said semiconductor device further has an operation mode of a deep power down mode with current consumption reduced relative to that of said power down mode, and said semiconductor device further comprises a second switch circuit provided between said main power supply line and a power supply node and disconnecting said power supply node from said main power supply line in said deep power down mode.