An electronic circuit comprising: a first semiconductor integrated circuit device configured to be operated by a first voltage, the first semiconductor integrated circuit device comprising: at least one regulator configured to step up or down the first voltage to convert the first voltage to a second voltage different from the first voltage and to output the second voltage; and a plurality of internal circuits (41, 42), wherein at least one of said internal circuits is configured to be driven by the first voltage and at leastanother one of said internal circuits is configured to be driven by the second voltage output by said regulator; and a second semiconductor integrated circuit device configured to be operated by a second voltage, characterized in that the first semiconductor integrated circuit device further comprises an output terminal configured to receive the second voltage from the regulator and to output the received second voltage to the outside of the first semiconductor integrated circuit device, and the second semiconductor integrated circuit device is connected to the output terminal and configured to be operated by the second voltage output from the output terminal. a first semiconductor integrated circuit device configured to be operated by a first voltage, the first semiconductor integrated circuit device comprising: at least one regulator configured to step up or down the first voltage to convert the first voltage to a second voltage different from the first voltage and to output the second voltage; and a plurality of internal circuits (41, 42), wherein at least one of said internal circuits is configured to be driven by the first voltage and at leastanother one of said internal circuits is configured to be driven by the second voltage output by said regulator; and a second semiconductor integrated circuit device configured to be operated by a second voltage, characterized in that the first semiconductor integrated circuit device further comprises an output terminal configured to receive the second voltage from the regulator and to output the received second voltage to the outside of the first semiconductor integrated circuit device, and the second semiconductor integrated circuit device is connected to the output terminal and configured to be operated by the second voltage output from the output terminal. at least one regulator configured to step up or down the first voltage to convert the first voltage to a second voltage different from the first voltage and to output the second voltage; and a plurality of internal circuits (41, 42), wherein at least one of said internal circuits is configured to be driven by the first voltage and at leastanother one of said internal circuits is configured to be driven by the second voltage output by said regulator; and a second semiconductor integrated circuit device configured to be operated by a second voltage, characterized in that the first semiconductor integrated circuit device further comprises an output terminal configured to receive the second voltage from the regulator and to output the received second voltage to the outside of the first semiconductor integrated circuit device, and the second semiconductor integrated circuit device is connected to the output terminal and configured to be operated by the second voltage output from the output terminal.