Word line selection circuit and row decoder
A first exemplary aspect of the present invention is a word line selection circuit where address decode signals composed of a power supply voltage and a first voltage lower than a ground voltage are input, and that a word line selection signal composed of the first voltage and a second voltage higher than the power supply voltage is output not via a level shift circuit according to the address decode signals.
1. A word line selection circuit comprising:
an inverter circuit that drives a boosted power supply potential VPP as a power supply, an output node of the inverter circuit being connected to a word line; and
a final stage row decoder that has a control output node output-wired to an input node of the inverter circuit, and that changes a potential of the control output node based on a result of having decoded groups of address control signals from a preceding stage row decoder, wherein
the final stage row decoder is provided with variable resistance means between the boosted power supply potential VPP and the control output node,
a resistance value of the variable resistance means is controlled by at least one of the groups of the address control signals, and
the groups of the address control signals from the preceding stage row decoder are signals of a non-boosted power supply potential,
wherein the variable resistance means is a PMOS transistor in which a source is connected to the boosted power supply potential VPP, a drain to the control output node, and in which one of the groups of the address control signals is applied to a gate,
wherein the final stage row decoder comprises an NMOS transistor whose gate is in common with the gate of the PMOS transistor, and wherein the NMOS transistor is connected in series with the PMOS transistor through the control output node, and
the groups of address control signals from the preceding stage row decoder are applied to the common gate and a source of the NMOS transistor.
2. The word line selection circuit according to claim 1 , wherein
one or more NMOS transistors are further provided at the source side of the NMOS transistor, and
the groups of the address control signals from the preceding stage row decoder are applied to gates of the one or more NMOS transistors and a source of an NMOS transistor arranged at the end of a transistor column.
3. The word line selection circuit according to claim 1 , wherein
one or more NMOS transistors are further provided at the source side of the NMOS transistor,
the groups of the address control signals from the preceding stage row decoder are applied to gates of the one or more NMOS transistors, and
a source of an NMOS transistor arranged at the end of a transistor column is connected to a negative power supply.
4. The word line selection circuit according to claim 1 , wherein
switching means that can be ON/OFF controlled is provided between the boosted power supply potential VPP and the variable resistance means, and
when a plurality of word lines are selected simultaneously, the switching means cuts off the connection between the boosted power supply potential VPP and the final stage row decoder.