Input circuit and output circuit

An output circuit which produces an external signal at a first voltage from a internal signal at a reduced second voltage and which outputs the external signal from an output terminal, comprising:

• first and second MOS transistors of which drains are connected to the output terminal, and of which gates connected to a control signal line;
• a third MOS transistor having a source connected to a power source of the first voltage, and having a drain connected to a source of the first MOS transistor;
• a fourth MOS transistor having a source connected to a ground, having a drain connected to a source of the second MOS transistor, and having a gate connected to an internal signal line;
• a voltage changer, which changes the voltage of the internal signal, connected to the gate of the third MOS transistor;
• a first diode connected between a gate of the first MOS transistor and a gate of the third MOS transistor;
• and
• a second diode connected between a gate of the second MOS transistor and a gate of the fourth MOS transistor.

An input circuit which produces a internal signal at a reduced second voltage from an external signal at a first voltage and which inputs the internal signal to an input terminal, comprising:

• a first MOS transistor having a source connected to a first terminal at the second voltage, and having a gate connected to the input terminal;
• a second MOS transistor having a source connected to a drain of the first MOS transistor, and having a gate connected to a ground;
• a third MOS transistor having a drain connected to a drain of the second MOS transistor, and having a source connected to the ground;
• a fourth MOS transistor having a source connected to a gate of the third MOS transistor, having a gate connected to a line at the second voltage, and having a drain connected to the input terminal;
• and
• a capacitor connected between the gate of the third MOS transistor and the input terminal,