Patent ID: 8456944

Claim:
A decoder circuit of a semiconductor storage device, comprising: a word line selection circuit that includes voltage application MOS transistors corresponding to each of a plurality of word lines that apply a normal voltage in a predetermined normal operation to the word lines corresponding to memory cells selected among a plurality of memory cells positioned at a portion where the plurality of word lines intersect a plurality of bit lines, and that applies a high voltage higher than the normal voltage in a predetermined high voltage operation to the word lines; and a level shift circuit that outputs to the voltage application MOS transistors at least one of the normal voltage and a ground voltage lower than the normal voltage according to a selection state of the word lines in the normal operation, and that outputs to the voltage application MOS transistor at least one of the normal voltage and the high voltage according to a selection state of the word lines in the high voltage operation, wherein the voltage application MOS transistors of the word line selection circuit include PMOS transistors, wherein the word line selection circuit includes a control PMOS transistor that controls output of a voltage applied to the voltage application MOS transistors, the control PMOS transistor including a source to which the normal voltage is input when the word line selection circuit performs the normal operation and to which the high voltage is input when the word line selection circuit performs the high voltage operation, and a drain connected to a source of each of the voltage application MOS transistors, and wherein the level shift circuit includes a PMOS transistor including a source to which the normal voltage is input in the normal operation and to which the high voltage is input in the high voltage operation, and a gate to which the normal voltage is input when the word line is selected in the normal operation, to which the ground voltage is input when the word line is not selected in the normal operation, and to which the normal voltage is constantly input in the high voltage operation, a first DMOS transistor connected to the PMOS transistor in series, the first DMOS transistor including a gate and a source connected to a gate of the control PMOS transistor, a second DMOS transistor connected to the first DMOS transistor in series and including a gate to which is input a selection signal that becomes active when the word line is selected, a first NMOS transistor connected to the second DMOS transistor in series, the first NMOS transistor including a gate to which the selection signal is input, and a second NMOS transistor connected to the first NMOS transistor in parallel and including a gate to which the ground voltage is input in the normal operation and to which the high voltage is input in the high voltage operation, and a source to which the ground voltage is input in the normal operation and to which the normal voltage is input in the high voltage operation.